Kiekhefer was recalled from Triple-A Memphis on Wednesday.
As expected, Kiekhefer will come up to fill the roster spot vacated by lefty Tyler Lyons, who hit the DL with a stress reaction in his right knee. Kiekhefer has pitched 13 innings for the Cardinals on the season, posting a 4.85 ERA and 1.15 WHIP. He's fared better at the Triple-A level, where he holds a healthy 2.00 ERA across 27 innings.