Mayers was optioned to Triple-A Memphis on Monday.
EDGE Analysis
Mayers is likely unavailable for a couple of days after tossing three innings of relief in Sunday's extra-innings win over the Cubs, so the Cardinals opted to send him back to the minors in order to clear a roster spot for Monday's starter, John Gant. The 26-year-old now owns a 1.86 ERA across 9.2 innings of relief this season, so he'll be one of the top candidates to rejoin the big club when a fresh relief arm is needed.