The Dallas Mavericks made a major change Monday, parting ways with director of player health, performance and innovation Johann Bilsborough after two seasons, according to a source with knowledge of the situation. Bilsborough’s firing means the Mavericks will need a new voice in charge of their medical staff, which has been in a state of flux since former general manager Nico Harrison chose to dismiss director of health and performance Casey Smith in August 2023.
Bilsborough was let go after another injury-riddled Mavericks season, one that saw only three of the team’s players appear in 70 or more games. The Mavericks went 26-56 this season, their second-worst record since 2000.
After the Mavericks’ regular-season finale Sunday, coach Jason Kidd pointed toward the team’s injury issues as a main reason why Dallas underperformed expectations.
“That’s something that has been a problem here for the last couple years,” Kidd said. “Hopefully we can solve that and then be judged. For coaching. For playing. That’s fair.”
On the Mavericks’ first day of training camp in October, center Daniel Gafford suffered a right ankle sprain that was significant enough to sideline him for all of the preseason and Dallas’ first five regular-season games. Gafford tried playing through the pain, but it clearly limited him. He frequently subbed himself out of games while dealing with discomfort. He ultimately missed 27 games, 18 because of his sore right ankle.
Last summer, the Mavericks invested heavily in their frontcourt, giving Gafford a three-year, $54 million extension even with Anthony Davis and Dereck Lively II already on the roster. Their plan when they traded for Davis was to routinely roll out double-big lineups. But because of injury issues with all three big men, that rarely happened. Davis and Lively shared the court for 29 minutes before Lively underwent season-ending surgery on his right foot in December. Davis and Gafford logged 39 minutes together this season, a partnership that came to an end in February when Davis was traded to the Washington Wizards.
“We have to be healthy at some point,” Kidd said Sunday. “We want that to be next season. If that is, we can be judged.”
In May 2025, the Mavericks fired head athletic trainer Dionne Calhoun, who spent 21 seasons in Dallas, and athletic performance director Keith Belton, a former NFL fullback who was only with the Mavericks for one year. Belton was let go after he put Lively through an on-court workout the day before medical imaging confirmed that Lively was dealing with a stress fracture in his right ankle, a detail ESPN was first to report.
In July, Lively underwent surgery to remove bone spurs from his right foot. He played in the Mavericks’ first three games of the season before being sidelined by a right foot injury that required surgery.
Dallas acquired Lively in a draft-night trade in 2023. In his rookie season, Lively started 42 games for the Mavericks as they made a surprise run to the 2024 NBA Finals. But over the past two years, the talented 22-year-old center has appeared in just 43 games combined.
Multiple league sources told The Athletic that team governor Patrick Dumont inquired about the Mavericks’ medical staff this season as the team’s injury problems persisted. Dumont was heavily involved in the Mavericks’ decision to hold Davis out of the team’s Nov. 8 game against the Washington Wizards because of his belief that Davis still needed time to properly recover from the left calf strain he suffered in the team’s fifth game of the season.
Guard Kyrie Irving, who has not played since tearing his ACL in March 2025, is expected to be fully recovered when training camp begins in the fall. Lively’s status is less clear. The shot-blocking big man was still wearing a protective boot as of Sunday.
“I don’t know when or what to expect with D-Live right now,” Kidd said. “Understanding he’s off the crutches, hopefully soon, he’s in two shoes. I know that sounds funny, but he’s still in a boot. Then, having that process of (him) being back on the court. Hopefully, he’s ready for training camp. Medically, I can’t give you the answer today because I don’t know.”
Kidd argued Sunday that it was difficult to evaluate his team’s performance due to the number of injuries the Mavericks have dealt with over the past two years.
“You have to have guys in uniform,” he said. “We had two out for the whole season in D-Live and (Irving). I’m not saying we’re built around two guys, but those are two big pieces for us.”
As of early Monday afternoon, no other changes have been made on the team’s medical side, a source familiar with the situation said. Last fall, Dallas promoted Jana Austin to head athletic trainer and brought on Geoff Puls from the Chicago Bulls as the team’s head strength and conditioning coach.