Assistant Joe Mazzulla will serve as the Celtics’ head coach in the interim, Himmeslbach added.
Udoka is being disciplined for an inappropriate relationship with a fellow Celtics employee, according to Shams Charania of The Athletic. The relationship was reportedly consensual. It has yet to be determined if there is any discipline for the female involved in the relationship.
Udoka was scheduled to meet with reporters on Monday for Celtics Media Day. Boston opens training camp a day later.
“Perhaps in the next 24-48 hours. I think that is coming. This is moving quickly here in recent days. For this Boston organization on the cusp of training camp scheduled next week, this is certainly a significant derailment for them.”
Udoka arrived in Boston after one season as an assistant under Steve Nash with the Nets. He served as an assistant with the 76ers in 2019-20, and for seven years with Gregg Popovich and the Spurs before that.
Prior to his coaching career, Udoka was a small forward with the Lakers in 2004, then spent time with the Knicks, Trail Blazers, Spurs and Kings from 2006-11. He also played professionally overseas.
According to ESPN Stats & Information, Udoka “became the first rookie coach to win multiple Game 7s in his first postseason,” Wojnarowski wrote.