Mayers (shoulder) was activated from the 10-day disabled list Tuesday.
Mayers is back with the Cardinals after spending a little more than two weeks on the shelf with a shoulder injury. He made one rehab appearance before being cleared to return, allowing just one hit across a scoreless inning for Triple-A Memphis. Mayers, who owns a 4.14 ERA and 1.30 WHIP with 42 strikeouts across 45.2 innings with the Cardinals this season, will be immediately available out of the bullpen for St. Louis.