Xavier Tillman slimmer after recurring knee injury sparked struggles

BOSTON — Xavier Tillman changed his diet, focusing on chicken, salmon and rice this offseason on his way to losing 12 pounds — something he believes should aid the recovery a March stem cell injection initiated after his left knee swelling returned in January. He fell out of the Celtics’ rotation early to begin the first season of a two-year deal following the 2024 championship he contributed to, and didn’t play any significant minutes into 2025.

”From a playing perspective, it was very hard, wanting to play, wanting to contribute,” he said after practice on Tuesday. “But I was going through stuff myself, like my knee would have days where it’d swell up into a balloon after I’d have one scrimmage, so I knew, consistency-wise, I could be there to support, but as far as my actual play, I couldn’t do everything I wanted to do.”

Following an intense first training camp practice where the big men even sprinted the floor as part of a new fast-paced attack the Celtics are employing, Tillman appeared long after the court cleared for his first session with reporters since a spot start in his return to Memphis. He spent the time between his press conference and the end of practice stretching, a routine he started surprisingly late in his career as an effort to loosen his hips and calves, alleviating knee pain that started following a meniscus tear in 2024, when the Celtics acquired him from the Grizzlies. He missed six of his first seven games with Boston, eventually returning to the floor and becoming a depth contributor to their title run.

Tillman underwent surgery that offseason to address frequent swelling in the knee, and that held up into next season where he didn’t land on the injury report until the spring, when aforementioned troubles began. The injection he received in March worked better than the scope and he dealt with minimal knee trouble this summer. The weight loss, improved health and open door for playing time at center reinvigorated him into this new year where he’ll play alongside Chris Boucher, Neemias Queta and old friend Luka Garza, who he competed with in high school and college.

”This is a different vibe of training camp than before with a lot of young guys so we got after it,” Tillman said. “Running around a lot, coaches screaming, you’re turning your head getting to the next spot. It was fun.”

Brad Stevens was non-committal about naming a front-runner at center on Media Day despite giving Queta a good shot following a strong offseason and continuous growth into his third season with Boston. Teammates have praised Garza’s summer improvement and early workouts, while Boucher should play significant minutes between the four and the five. That leaves some uncertainty over what’s left for Tillman, though Stevens mentioned him also playing multiple positions in larger lineups over the summer as an answer for key offseason losses Kristaps Porziņģis, Luke Kornet and Al Horford.

Tillman turns only 27 next year, and mentioned learning from those veterans about professional habits. He hired a chef this offseason, and shot threes tirelessly. His strength remains defense, and he may prove versatile enough on that end to enter the rotation on a team that needs to find perimeter stops and rim protection. Joe Mazzulla, a spacing advocate, may hesitate to play lineups with limited shooting, but the depth situation at center should call for at least some minutes from a player who proved intriguing after his addition at the 2024 deadline and produced one of the most compelling moments of the Finals with his corner three. He became easy to forget since, and declared that he’s back to begin 2025-26.

“You’ll see my defense come back again where I’ll make cuts and do things where it’s like, ok, you can really switch and guard 1-5 and it’s because of my knee health,” Tillman said. “I got it back in the right direction.”