The Toronto Maple Leafs have hired acclaimed strength and conditioning coach Andy O’Brien to lead a revamped Sport Performance department, according to league sources, speaking on condition of anonymity to discuss negotiations that aren’t public. The move continues the Leafs’ massive organizational overhaul following a 28th-place finish.

O’Brien is best known for his work as Sidney Crosby’s personal strength and conditioning coach of more than 20 years. He’s also worked with several other top NHL players, including Nathan MacKinnon, Taylor Hall and Maple Leafs forward John Tavares, and contributed to four Stanley Cup victories — two as a high-performance consultant with the Florida Panthers in 2024 and 2025, and two as director of sports science and performance with the Pittsburgh Penguins in 2016 and 2017.

With the Leafs, O’Brien will oversee every domain related to performance optimization. That covers strength and conditioning but will also include areas such as nutrition, injury rehabilitation and sport science.

Hiring the 48-year-old is a big splash for new general manager John Chayka, who has been aggressive since stepping into his role on May 3. He’s since cut ties with several longstanding members of the front office, installing his own people in key scouting and player evaluation roles while bringing in an entirely new coaching staff under Jim Hiller.

Chayka also turned over roughly half the NHL roster through trades and free-agent signings.

O’Brien will build out his own team of professionals to support the off-ice performance and development of those players. It’s an area where an organization with strong financial backing can seek to find an edge.

O’Brien has long been a highly sought-after strength and conditioning coach in NHL circles, both through his private practice and the high-performance camps he runs at altitude in Vail, Colo., each summer, which consistently draw MVPs and All-Stars. Connor McDavid, Cale Makar, Mitch Marner, Macklin Celebrini, Connor Bedard and Patrick Kane are among those who have attended more than once.

Then there is the work he does with Crosby, which started when Crosby was still a teenager and O’Brien was just starting to get established by helping athletes develop what he called “functional moving efficiency.” The Pittsburgh Penguins captain told CBC in an interview last year that O’Brien has played a big role in shaping his career.

“When I first met Andy, it was all just about trying to move,” Crosby said. “You want to get strong and build that way, but at the same time, you’re just trying to be an athlete. He was really helpful in that. I think when you spend so much time with someone, I think they have such an important role. You’re motivated every day, but at the same time, there’s always challenges, and to have somebody there in your corner to get you to the level that you want to be at, he’s someone I can definitely depend on.

“He’s a trainer, but he’s also a friend.”

Steve Simmons of the Toronto Sun was the first to report O’Brien was being hired by the Leafs.