McGary suffered the injury Wednesday in the Thunder's preseason opener against the Nuggets, a 114-101 loss. McGary started at power forward in place of Serge Ibaka (ankle) and was impressive in 36 minutes, scoring 14 points on 7-of-14 shooting with four rebounds and two assists. McGary flashed a keen offensive ability, syncing up with center Steven Adams on a number of possessions.
Kevin Durant has consistently praised McGary's play and enthusiasm during training camp.
"He's such a great teammate and you want to do as much as you can for him," Durant said Monday. "I love playing with him. He plays extremely hard. He listens. He wants to get better. He helps us get better as well. He's a smart basketball player."
McGary, selected 21st overall, missed all but eight games of his sophomore season at Michigan because of back issues that eventually resulted in surgery. He recently said at the beginning of the Thunder's training camp that he was "100 percent healthy." McGary was expected to battle for minutes in the Thunder's frontcourt rotation, possibly pulling minutes away from 34-year-old veteran Nick Collison, who had arthroscopic surgery on his knee during the summer.