The Cardinals added Leahy to their active roster for Saturday's doubleheader against the Cubs, Jeff Jones of the Belleville News-Democrat reports.
Leahy owns a 4.13 ERA and 1.09 WHIP through 28.1 innings in the majors this season, and he'll now return to St. Louis in order to add extra depth to the bullpen for Saturday's twin bill. He'll likely be returned to Triple-A Memphis after the conclusion of the second game.