Andrew Bynum suffered an unspecified injury this month while bowling, according to multiple sources.

"I had a little bit of a setback, and we're just working through some issues with the right knee," Bynum said on Friday. "I kind of have a mirror thing going on with my left knee. I don't know what's going on, but the doctors are saying pretty much that it's a weakened cartilage state."

Bowling is not an activity prohibited by standard NBA player contracts.

Bynum's debut with the Philadelphia 76ers has already been postponed multiple times.