The Cardinals recalled Mathews from Triple-A Memphis on Saturday ahead of his start against the Phillies.
Mathews will return to the majors to help fill the holes in a St. Louis rotation that has lost both Andre Pallante (elbow) and Hunter Dobbins (forearm) to the injured list within the past couple of days. Mathews owns a 3.27 ERA at Triple-A this season and has given up just three runs across nine innings during his two starts in the big leagues.