In placing Koehler on the DL, the Marlins have pivoted from their original decision to option the pitcher to Triple-A New Orleans. Koehler had been optioned to the minors following his Tuesday start against the Astros, in which he allowed eight runs in three innings to raise his ERA to 7.04.
Tuesday's announcement that Koehler would be optioned was a surprise, as Koehler had been in the rotation since 2013 and made at least 31 starts for Miami in each of the last three seasons. He began 2017 as the club's No. 3 starter.
"I've dealt with adversity my whole baseball career," Koehler said Tuesday. "That doesn't stop now. I truly believe I belong in the big leagues. I've shown that. I've done this a long time now. It's just getting back to what I do well and getting back to finding ways to help this team win."
Koehler, 30, has struggled to work deep into games this year. In eight starts, he's completed six innings on two occasions.
The Marlins are also without left-handed starter Wei-Yin Chen, who has been on the DL since May 5 with left arm fatigue.
The Marlins also outrighted infielder Steve Lombardozzi to New Orleans. Lombardozzi was previously designated for assignment Tuesday.
Austin Laymance is a reporter for MLB.com based in Los Angeles. He covered the Marlins on Thursday. This story was not subject to the approval of Major League Baseball or its clubs.