The Celtics have a secret weapon: ‘One of the greatest humans in the world’

BOSTON – During every single timeout, Joe Mazzulla and four Celtics’ assistant coaches huddle up on the court. In the center is former NBA star Sam Cassell, one of the team’s most veteran (and vocal) sideline presences. There’s Matt Reynolds, the franchise’s longest-tenured assistant — and the coach most responsible for determining when the team […]