The team made the announcement before Sunday's game at Minnesota. Coach Dwane Casey says Patterson has been bothered by the injury for some time, but aggravated it on Friday in a win against Sacramento.
It's a big loss for the Raptors, who have taken off since acquiring Patterson from Sacramento as part of the trade that sent Rudy Gay to the Kings on Dec. 9.
Patterson is averaging 9.7 points, 5.2 rebounds and 23.4 minutes per game with Toronto. He has shot 44 percent from 3-point range and also brought a defensive tenacity to the Raptors' reserves that has made a big difference.