Leahy is with the Cardinals and will be the team's 27th player for the nightcap of Saturday's doubleheader against Atlanta, Derrick Goold of the St. Louis Post-Dispatch reports.
Leahy will give the Cardinals and additional bullpen arm for Game 2 after St. Louis lost 3-2 in 10 innings during the matinee. Leahy has thrown 30.1 big-league innings with a 4.15 ERA and 1.09 WHIP. He'll likely be sent back to Memphis following the contest.