07/09/12 10:28 PM ET
Perez has torn ulnar collateral ligament
By Quinn Roberts / MLB.com
However, the left-hander will get a second opinion before determining his next step.
Perez has made 35 appearances for Toronto this season, going 2-2 with a 3.43 ERA.
He last pitched on Sunday against the White Sox, allowing two runs on four hits in one inning.
Quinn Roberts is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.