Mayers has been recalled by the Cardinals on Friday, Jenifer Langosch of MLB.com reports.
It'll be Mayers' third stint with St. Louis this season -- in the first, he gave up two runs in 4.0 innings, while he didn't throw a pitch in the second and stayed with the Cards for less than 24 hours. The former starter is still adjusting to his new role in the bullpen, but should see time in low-leverage situations as Luke Weaver leaves the bullpen to take the place of Adam Wainwright (back) in the rotation.