Key personnel within the Dallas Mavericks organization, including both current and former employees, along with close associates of Dirk Nowitzki, traveled together on the team`s plane in August 2023. The flight`s destination was Springfield, Massachusetts, for the celebration of Nowitzki`s induction into the Naismith Memorial Basketball Hall of Fame, honoring the franchise`s most iconic figure.
Mavs General Manager Nico Harrison was part of this trip. Although not particularly close to Nowitzki, their association dated back over two decades to when Harrison began his career at Nike as a regional field representative based in Dallas.
Casey Smith, Dallas` director of health and performance, also joined the team`s travel group for the weekend`s events. Nowitzki often credited Smith, who joined Dallas as head athletic trainer in 2004 and was promoted to an executive role 15 years later, with helping him extend his playing career to 21 seasons. Nowitzki placed immense trust in Smith, considering him one of his closest friends.
Those who attended the Hall of Fame festivities, which included elaborate private parties organized by Nowitzki`s longtime special projects manager Lara Beth Seager in addition to the Hall of Fame events, recall nothing appearing unusual that weekend in Springfield, where both Harrison and Smith were accompanied by their wives.
However, subsequent events triggered a series of behind-the-scenes decisions with significant repercussions for the Mavericks during a surprisingly difficult, disappointing, and injury-plagued season in Dallas. Interviews with over a dozen team and league insiders indicate that while the Luka Doncic era formally concluded on February 2nd, its true unraveling, along with the team`s culture, began 18 months prior – in the summer before the prodigious talent led the Mavs to the NBA Finals.
A few days after returning to Dallas Love Field from the Hall of Fame event, a time when the franchise was still riding a wave of positivity from honoring Nowitzki despite a frustrating losing season, Harrison informed Smith that he needed a meeting. Smith responded that an in-person meeting wasn`t possible as he was in his hometown in Ohio, supporting his gravely ill mother in her final weeks. Harrison then arranged a video conference call.
Smith was then informed that his services in Dallas were no longer required, ending a nearly two-decade tenure with the franchise. Sources briefed on the discussion indicated the reason cited for his dismissal centered on Smith being `too negative,` interpreting this vague explanation to mean Smith wasn`t sufficiently agreeable.
“He was absolutely intimidated by him,” a team source disclosed, referencing Harrison`s perceived concern that Smith`s influence within the franchise was too significant. “He wanted to demonstrate that he was in charge and that no one else could challenge that authority.”
This marked a significant initial step in Harrison`s restructuring of the team`s health and performance department over the previous two offseasons. Smith`s abrupt departure was followed by the dismissals of athletic performance director Jeremy Holsopple and manual therapist Casey Spangler in June, merely days after Dallas` appearance in the NBA Finals.
“Bringing up Casey [Smith] is almost like, it’s kind of a joke,” Harrison commented recently during a media availability with select Dallas reporters. “Last year, Casey wasn’t around, and we made it to the Finals. No one mentioned Casey last year. So, mentioning him this year doesn’t really make sense. He’s been gone for two years. So, I`m not even going to comment on that.”
Sources informed that the strained relationship between Doncic`s representatives – led by agent Bill Duffy and Seager, who became Doncic`s business manager after being introduced by Nowitzki – and Harrison and his new staff was a factor in the GM`s surprising decision to trade Doncic to the Los Angeles Lakers for Anthony Davis in February.
Smith, Holsopple, and Spangler were all long-serving Mavs employees who had helped Doncic, a Slovenian who spent his teenage years in Spain, adapt significantly to the culture change upon arriving in Dallas. They had become trusted advisors for the superstar. However, sources indicated that Harrison viewed them as `enablers` of Doncic, despite their immense respect among peers throughout the league. Holsopple was named NBA Strength and Conditioning Coach of the Year in 2021, and Smith`s tenure as Team USA`s head athletic trainer included winning gold medals at the 2008 and 2012 Olympics.
“We feel the individuals who replaced them have done an outstanding job,” Harrison stated. “Again, you`re approaching this from a negative perspective, while I view it positively. The people we brought in are superior.”
Multiple sources noted that friction between Harrison`s new hires – director of player health and performance Johann Bilsborough and athletic performance director Keith Belton – has caused issues as the Mavericks faced numerous injuries throughout the season. The team did not employ a full-time manual therapist this season. At one point late in the season, Dallas struggled to field the league-minimum eight active players, dropping below .500 before finishing 39-43 and securing the Western Conference`s final play-in spot.
Harrison`s decision to fire Smith, and the manner in which it was done, also created distance between Nowitzki and the franchise he proudly represented his entire career. Sources indicated that Nowitzki, who now identifies himself as a `Mavs fan,` chose to step back from involvement in the team`s basketball operations following Smith`s forced exit. Previously, Nowitzki had served as a senior adviser to Mark Cuban, frequently attending practices and offering input when in Dallas.
Sources also revealed that Smith`s removal prompted the departure of Mavs vice president of basketball communications Scott Tomlin, another employee of over two decades who was close with Smith, Nowitzki, and Doncic, among others. Tomlin accepted a position as the executive director of the DN Companies and The Dirk Nowitzki Foundation.
“My commitment is to the Dallas Mavericks,” Harrison said recently. “It`s about what is in the best interest of the Dallas Mavericks, and that is paramount. Again, some of these decisions may be unpopular, perhaps with Dirk or with the fans, but my obligation is solely to the Dallas Mavericks.”
Since the beginning of February, Nowitzki and Tomlin have attended two NBA games: Doncic`s debut with the Lakers in Los Angeles on February 10th and his return to Dallas on April 9th.
“Over the past year, you could already see the team heading in a different direction,” Nowitzki, who declined an interview request for this article, recently said in German on his foundation`s Campus 41 podcast. “Now we are witnessing the outcome of that.”
DERECK LIVELY II, a 21-year-old center considered a key piece for the future, was listed as questionable on January 20th due to a right ankle sprain, having already missed the previous two games. Under Belton`s oversight, Lively underwent an intensive return-to-play workout before again being sidelined that night.
The original plan was for Lively to play at home two nights later against the Minnesota Timberwolves.
However, Bilsborough had reservations, prompting him to send Lively for a CT scan. The scan revealed a stress fracture in his right ankle, which kept the center out for the following 2½ months.
“Someone should be held accountable for that,” a team source commented at the time.
Multiple team sources indicated this incident was indicative of a much broader issue.
Harrison, conversely, framed the handling of Lively`s injury as evidence that his medical staff is “elite,” as he stated recently. Sources noted that Lively`s representatives were satisfied with Bilsborough`s communication and collaboration throughout the recovery and rehabilitation process.
“It actually demonstrates the strength of our medical team, because he was cleared to play, but his signs and symptoms indicated to our medical team that something more was wrong,” Harrison explained. “That`s why they re-tested him and saw the CT scan, which actually prevented a potentially devastating injury. So, you can take a negative view, but it`s actually a positive outcome because based on the symptoms, even though he was cleared to play, they didn`t feel comfortable putting him on the court.”
“They stopped him from playing. They went back. They retested, and thankfully, we discovered he had a stress fracture.”
According to more than 10 team sources, the situation culminated in a loud, heated argument between Bilsborough and Belton that began in the trainer`s room at the practice facility and continued into the weight room. Harrison did not respond to inquiries about this incident – or several others concerning the health and performance group – submitted through the Mavs` media relations department. The Mavericks declined requests to make Bilsborough or Belton available for comment.
“Not physical blows, but they were intensely arguing,” one of many sources who saw surveillance footage of the incident recounted.
“That confrontation had been brewing for a long time,” another team source added.
THE TENSION HAD been escalating for months. Harrison created an awkward dynamic by agreeing to hire Belton before Bilsborough, despite Bilsborough being the head of the department.
Sources indicated Bilsborough does not respect Belton`s expertise.
“He`s essentially a glorified cheerleader,” one team source commented. “But Nico clearly desired a cheerleader type of energy.”
According to the National Strength Coaches Association database, Belton does not hold either of the certifications from that association required for NBA strength coaches under Article XXII of the collective bargaining agreement. The CBA mandates that an individual hired as a head strength and conditioning coach must possess at least three years of experience since obtaining those certifications.
An NBA spokesperson stated that the league office was aware Belton lacked the required NSCA certifications but accepted his certifications from the College Strength and Conditioning Coaches Association on a temporary basis, with the understanding that he would obtain his NSCA certifications immediately after the season. Belton`s UCLA biography noted that he “was a winner of the prestigious Stucky Award given to individuals who excelled during the practical section of the exam.”
Some critics of Belton describe him more as a personal trainer than the `body engineer` role that is standard for modern NBA strength coaches.
“Johann`s influence in his department is somewhat limited,” a team source said. “[Belton is in] a crucial position that involves training players but also ensuring the department aligns with a consistent philosophy and everyone works collaboratively – [Belton is] none of those things. Furthermore, the two have been in conflict since the beginning, which led to the major blowup.”
“He has shown no respect towards Johann throughout the year. Zero collaboration. His behavior ranges from being completely distant to doing incredibly foolish things with a player simply to prove a point to Johann. It`s terrible. And you cannot operate that way. His actions and lack of collaboration inevitably put players at greater risk.”
Belton, a former NFL fullback, had no prior NBA experience before this season. He had spent the previous four years as the director of football performance at UCLA, among several college roles primarily focused on football.
Bilsborough, an Australian sports scientist with a doctorate, also came to the Mavs from the football world, having spent the preceding five seasons as the New England Patriots` director of performance and rehabilitation. He also had previous NBA experience, serving as the Boston Celtics` director of sports science from 2017 to 2020.
A Celtics source described Bilsborough as a highly intelligent academic expert, though less of a hands-on practitioner, and someone who tends to be “confrontational when he disagrees with someone.”
Bilsborough and Art Horne, the Celtics` head athletic trainer and director of performance at the time, frequently disagreed. They had no prior relationship but were hired in the same offseason to co-lead Boston`s health and performance group.
“That was problematic,” the Celtics source stated. “There was a cold war. You had Art Horne`s supporters and Johann`s supporters.”
Celtics sources reported that communication between factions within the department was infrequent and unproductive. Bilsborough departed the Celtics after three seasons. Horne remains in Boston, having been promoted to director of organizational growth and team development in 2022.
Bilsborough struggled to build a connection with Doncic and the five-time first-team All-NBA selection`s personal `body team.` Harrison had already strained his relationship with Doncic by removing people the player trusted and respected. Sources said Bilsborough, who faced the difficult task of replacing Smith, never earned Doncic`s trust or respect.
It is likely not a coincidence that Jalen Brunson`s New York Knicks hired Smith as their vice president of sports medicine as soon as his Mavericks contract expired last summer. New York also brought in former Mavs athletic trainer Heather Mau. The number of games lost to injury for the Knicks has decreased significantly from last season, and Smith and Mau recently oversaw Brunson`s recovery from a severe ankle sprain.
Weeks after leaving the Mavs in free agency in 2022, Brunson discussed how much he would miss “the Caseys” (Holsopple and Mau) during an appearance on JJ Redick`s `Old Man and the Three` podcast. Redick mentioned he was still in an active group chat with those former Dallas staffers despite only spending two months with the Mavs at the end of his playing career a year prior.
“Many people don`t realize the profound impact those individuals have on your daily life,” Brunson said. “I never take that for granted. They are truly special. And the fact that they are so approachable and you can discuss anything with them makes leaving the Mavs even harder. It wasn`t just about work. They understood how to connect on a personal level.”
Sources within the Mavericks, as well as agents and associates of current Dallas players, have mixed opinions on Bilsborough. Some describe him as evidence-based and capable, while others are critical. Common complaints include that he doesn`t establish strong relationships with players or staff, doesn`t travel frequently with the team early in the season, and occasionally provides overly optimistic timelines for players returning from injury.
“If you`re not constantly present with the team, you shouldn`t be involved in decision-making,” a team source asserted.
Another team source who otherwise praised Bilsborough added, “That is definitely a challenge. You can`t be perceived as someone who just shows up occasionally. You need to be integrated, and obviously, that was Casey`s special quality.”
Harrison defended the Mavs` health and performance group, pointing out that the vast majority of injuries sustained by Dallas players this season have been unavoidable and caused by contact.
However, on multiple occasions, Mavs players have re-aggravated injuries or sustained related injuries immediately upon their return.
“It`s difficult to judge the medical staff solely on contact injuries, but how quickly players return and how likely they are to get reinjured – that`s a different matter,” a team source commented. “How do you facilitate my return? How effective am I upon returning? That falls under the medical and performance staffs.”
Another team source added, “I believe that is where you truly see the impact of the dysfunction, and not just within the medical department, but also the pressure to keep the team afloat until other players return so that the front office can justify its prior decisions. There seems to be organizational dysfunction stemming from the trade itself.”
The most significant and costly example is the left adductor strain suffered by Davis during his Dallas debut on February 8th. This occurred upon his return from an abdominal strain sustained on January 28th, days before the trade.
With Harrison facing scrutiny, Davis was motivated to make a strong initial impression on the frustrated Mavericks fan base in the first home game following the surprising blockbuster deal. He admitted he probably should have waited another game or two to return but stated the decision was his, made in consultation with his personal medical team and Bilsborough.
“They meet and communicate daily,” said Davis, who works with his own staff in the weight room rather than Belton. “Everyone is working together as one big team.”
According to multiple sources, that description does not accurately reflect the dynamic between Bilsborough and Belton, stating their conflict has been detrimental to the team.
“In all successful organizations, the performance and medical staffs function seamlessly,” a team source observed. “Here, they are completely separate and at odds. The impact of this divide is quite apparent. The division created an unfortunate environment that ultimately affected the players.”
MONTHS BEFORE SMITH`S departure, Doncic and Seager had hired Real Madrid physiotherapist Javier Barrio Calvo and Slovenian national team strength coach Anze Macek – both well-known to Doncic – to work for him personally. This followed his persistent quadriceps injury, which contributed to the Mavericks` poor performance leading into the 2023 draft lottery. This trend of NBA superstars, including Davis and Mavs guard Kyrie Irving, employing personal health and performance staff to work in consultation with their team`s department has become increasingly common.
Doncic and Seager had envisioned his personal staff collaborating smoothly with Smith, who made annual summer visits to Slovenia and often attended Doncic`s national team games globally. With Smith dismissed for the final year of his contract, Holsopple became the Mavericks` primary contact point in the coordination with Doncic`s body team.
Doncic`s camp considered the first season of this arrangement a great success. He averaged a league-leading 33.9 points, 9.2 rebounds, and 9.8 assists during the regular season and became the first player in NBA history to lead the league in points, rebounds, assists, and steals during a postseason run. He also led the league in total minutes played with 3,524 combined in the regular season and playoffs.
“You don`t perform like that… if you`re out of shape or not dedicated,” a friend of Doncic`s lamented, feeling as though that`s how the Mavericks organization portrayed the superstar in the aftermath of the trade, which ended Doncic`s aspiration to spend his entire career in Dallas.
Despite the remarkable production, Harrison was concerned Doncic had still gained weight during the season while managing a heavy workload. The tension escalated between the GM and the increasingly isolated face of the franchise and his representatives. Bilsborough stepped into a challenging situation and did not manage to build rapport with Doncic`s camp.
Sources indicated that Cuban, who had made Doncic`s satisfaction a top priority since Dallas acquired his draft rights in 2018 and had worked closely with Seager for years prior, volunteered to mediate. However, Harrison had successfully marginalized Cuban from basketball operations since Patrick Dumont became the team`s governor and was unwilling to concede any authority, sources said.
Compounding the issues, Doncic sustained a blow to his left calf while scrimmaging with teammates at SMU just before training camp commenced. It was initially believed to be just a bruise, but after Doncic experienced significant soreness during the opening practice of camp, an MRI revealed a Grade 1 strain, sources stated, which the Mavericks did not disclose in their official injury report.
Doncic missed the preseason and reportedly gained over a dozen pounds during his absence, sources revealed, frustrating and angering Harrison and others within the organization.
Doncic, who also utilized his personal team of doctors instead of the Mavericks` physicians, was diagnosed with a sprained right wrist on November 20th. Sources indicated Harrison and the Mavericks` medical staff viewed this diagnosis as a way to allow Doncic time to improve his conditioning and lose weight after a slow start to the season by his standards.
On November 29th, the day before the fifth and final game he missed, a television in the media room at the Mavericks` practice facility was tuned to a closed-circuit feed of Doncic scrimmaging with players receiving limited minutes and staff, frequently attempting long jumpers. When a team employee noticed the feed, they quickly changed the channel, claiming they were unsure how it became accessible. The feed has not been shown in the media room since.
Barrio Calvo and Bilsborough communicated regularly but frequently disagreed, sources said. Meetings involving Harrison, Bilsborough, Seager, Barrio Calvo, and Duffy were often tense and unproductive. Doncic did not work with Belton at all.
Tension between the parties soared after Doncic sustained another left calf strain – his fourth in 28 months – on Christmas Day. Doncic`s camp believed he had returned too quickly from a left heel bruise suffered during his 45-point triple-double in a December 15th victory and had been playing on his toes to avoid heel discomfort. Harrison attributed the injury to poor conditioning.
The two sides also drastically disagreed on the recovery timeline for Doncic after receiving the MRI results. Bilsborough believed Doncic could return in two or three weeks, sources indicated, while Doncic`s team strongly asserted he needed to sit out for six weeks. They ultimately prevailed, and a target return date was set for the February 8th home game against the Houston Rockets.
“That significantly widened the gap between the sides,” a source commented.
Doncic avoided putting weight on his left leg for two weeks, using crutches and a scooter. MRI results four weeks later were positive, but the six-week plan remained in effect.
Another major disagreement arose when Doncic refused Harrison`s request to travel with the team on a five-game road trip leading up to his planned return date.
Sources reported that Harrison complained that Doncic was holding the team “hostage.”
Doncic`s camp argued that he benefited more from having round-the-clock access to the Mavericks` practice facility than from traveling with the team. They pointed out that Doncic was doing multiple daily, multi-hour basketball workouts, which would be impossible to schedule consistently on the road. He also had convenient access to the weight room and advanced medical equipment, which isn`t typically available in other teams` arenas and hotels.
Harrison countered, insisting that Doncic needed to participate in scrimmages. Doncic`s camp responded by saying he would be happy to practice with the G League Texas Legends in Frisco, a Dallas suburb.
The next communication Doncic`s camp received from Harrison was the announcement that the trade he had been secretly negotiating with the Lakers for weeks was finalized.
