The Boston Celtics announced Friday that they have signed head coach Joe Mazzulla to a multi-year contract extension. The team didn't disclose the terms of the deal, however. "We are very excited that Joe has agreed to extend with the Celtics," said Brad Stevens, the Celtics' president of basketball operations. "He understands the job and has a passion for the Celtics that is only rivaled by our most die-hard fans. He's worked hard and accomplished amazing things in his first three years as a head coach — including averaging over 60 wins per season and winning the 2024 NBA Championship. "Joe is a gifted leader who brings a consistent commitment to learning, improving, and maximizing each day we get to compete for the Boston Celtics." This story is being updated.