The club announced Monday night that left-handed reliever Luis Perez will miss the rest of the season with a torn ligament in his throwing elbow.
The Jays say Perez will get a second opinion before a course of action is determined, but Tommy John ligament-replacement surgery is often recommended for similar injuries.
Blue Jays starter Kyle Drabek is already out for the year after tearing the same ligament in his pitching elbow. He underwent Tommy John surgery last month.
The Jays have had seven pitchers on the disabled list this season at one time or another and are currently without starters Drew Hutchison (elbow sprain) and Brandon Morrow (strained rib cage muscle).
Perez has made 35 appearances in relief this season, going 2-2 with a 3.43 earned-run average.
The 27-year-old was placed on the 15-day disabled list Sunday with left elbow tightness. He left Toronto's 11-9 win over the Chicago White Sox with a team trainer in the seventh inning after giving up hits to Alex Rios and Alexei Ramirez.
There was no immediate word on a corresponding roster move.