Initially, the Marlins were leaning toward having the right-hander rejoin the rotation sometime next week. But as of Wednesday, nothing has officially been announced as to whether Cosart will return to the club or make another rehab assignment start.
"To be determined," manager Dan Jennings said.
On the disabled list retroactive to May 14 with vertigo, Cosart threw 5 1/3 innings on Tuesday night in a rehab outing for Triple-A New Orleans at Round Rock. The 25-year-old gave up four runs on seven hits with two walks and six strikeouts in a no-decision.
Cosart ran his pitch count up to 103, with 67 strikes.
In seven starts with the Marlins, Cosart is 1-3 with a 4.08 ERA, and he last saw action on May 13 at the Dodgers.
Jennings said he still must meet with the front office to determine what to do with the rotation.
"We'll come up with what is going to be our best plans going forward," Jennings said.
Jennings noted that competition may decide who stays and who goes to the bullpen.
Cosart and Jose Fernandez (Tommy John surgery) remain on the disabled list. Fernandez has announced he will return to the rotation on July 2 at home against the Giants. His status is secure.
Cosart's situation could be different.
"Competition is a great thing," Jennings said. "If someone is going to take a job, it's one thing. They have to earn it. Urena has pitched very well. I love the competition."
Fernandez's spot is locked in. But once Cosart and Fernandez return, at least one or maybe two starters currently in the rotation may wind up in the bullpen.
Jennings didn't say if Cosart could be a bullpen option. Perhaps his performance, coupled with how Urena, Phelps and Koehler are throwing, will play a factor.
"Jose [Fernandez] is Jose, and he's a true No. 1," Jennings said. "But the competition is good."
Joe Frisaro is a reporter for MLB.com. He writes a blog, called The Fish Pond. Follow him on Twitter @JoeFrisaro and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.