The All-Star center was acquired from the Los Angeles Lakers in a four-team trade before the season. He had been recovering from a bone bruise on his right knee, and his return has now been pushed back four times since the beginning of training camp.
The Sixers were hoping Bynum would be cleared to return to basketball activities by Dec. 10 before he injured his left knee while bowling two weeks ago.
Sixers general manager Tony DiLeo says Bynum has “bilateral bone bruises and a weakened cartilage state” in his knees. Still, DiLeo defended the trade that sent All-Star forward Andre Iguodala to Denver in the multiteam deal.