Bulls center Joakim Noah will miss at least two weeks because of a sprained left shoulder.
Noah exited Monday's loss to the Brooklyn Nets in the third quarter.
He was on defense when Brooklyn's Andrea Bargnani, after jumping, came down hard on Noah's left arm, bending it back awkwardly. Noah, who was called for a foul on the play, ran around the court in obvious pain with his left shoulder slumped over for a moment before heading off the court and into the tunnel leading to the locker room.
He had an MRI on Tuesday and will be re-evaluated in two weeks. Noah is averaging 4.5 points and 8.8 rebounds.
The Bulls (15-11) have dropped three straight.