The Boston Celtics, facing significant roster changes including the loss of key players and potentially Jayson Tatum for the 2025-26 season, aim to become the NBA’s “hardest-playing team” under head coach Joe Mazzulla, according to assistant coach Sam Cassell. Their rigorous training camp features intense three-hour sessions that combine individual work and strength training, emphasizing a high-energy play style to exceed expectations this season.
