Bynum did not travel with the team to Boston for Saturday's game against the Celtics. He was excused from all team activities indefinitely.
The Cavaliers said they will update his status at a later time.
The team has until Jan. 7 to decide on guaranteeing his contract for the rest of the season. Bynum signed a two-year, $24 million deal in the summer but only $6 million is guaranteed.