Peters will remain in the majors as a long-relief option for now, Clark Spencer of the Miami Herald reports.
There was an expectation that Peters would be sent back to the minors as a corresponding move to Dan Straily's activation from the disabled list, though the Marlins opted to make a different move. Despite this, manager Don Mattingly reiterated that the Marlins prefer the southpaw in a starting role, so he'll likely find his way back in Triple-A soon if a big-league rotation spot doesn't open up. In five starts for Miami this season, Peters has a 5.84 ERA and a 1.58 WHIP.