Koehler, 31, made 131 starts out of the Marlins’ rotation over the last five years, but his 12 this season have not been good, so the club hopes he can figure things out with a stint in the minors. He’s carrying a 7.92 ERA with a 44/29 K/BB ratio in 55 2/3 innings. Koehler battled bursitis in his right shoulder in May and June, which may partially explain his struggles.
Cervenka, 27, posted a 4.50 ERA with a 34/21 K/BB ratio in 34 innings of relief with New Orleans. He hasn’t pitched in the majors yet this season, but compiled a 3.53 ERA over 43 1/3 innings in the bigs last year in the Marlins’ bullpen.