Tim Duncan left Wednesday's game early in the second half after suffering a chest contusion and will undergo further evaluation on Thursday, leaving him questionable for Friday's game at the Lakers. "He'll get checked out tomorrow," Gregg Popovich said. "He had spasms in his shoulder and his neck. It looks like his chest is bruised. He caught an elbow, so it kind of affected (him) from his chest up through his neck at some time or another." If Duncan can't go on Friday, look for Boris Diaw to pick up the start in his place.