Manager Cito Gaston made the announcement Tuesday before the Blue Jays played the Texas Rangers.
Litsch went on the disabled list April 14 because of tightness in his forearm. He made two starts this season, going 0-1 with a 9.00 ERA.
Gaston was more optimistic about his other injured pitchers, who have been on the DL all season. McGowan is recovering from a shoulder injury and Marcum, who had elbow surgery, "is getting better all the time."