The Cardinals are set to promote Jorge Rondon to the Major League Club on Thursday, according to former Cardinal Eduardo Sanchez; it's expected that Keith Butler will go back to Memphis. The move is being made for two reasons: Butler has struggled in his only two outings and starter Joe Kelly strained his hamstring running to first base in Wednesday's loss to Milwaukee.
Rondon, optioned to Memphis on March 28, pitched well in the spring but has struggled since the season has started; in 5.0 innings, he's allowed 6 hits and 3 earned runs. He hasn't walked anyone, but only has 2 strikeouts. This will be his first time on the 25-man roster.
Kelly is expected to miss only one start due to his injury; he came up lame after attempting to reach base on a bunt and left the game in the top of the 5th inning. Hey is traveling with the team to Washington DC before returning to St. Louis to be re-evaluated on Thursday. Tyler Lyons is expected to be recalled from Memphis to make the start Monday. Carlos Martinez is not being considered for the start, as he's been one of the more reliable parts of the bullpen.
Butler has struggled in his short MLB career; this season, he's given up 6 earned runs and 6 hits in 2 innings. Overall, he owns a 6.14 ERA across 22 innings; in the minors, he had a 2.29 ERA over 212 innings.