Petersen was lifted midway through the fifth inning of Sunday's game against the Guardians due to a right hamstring injury, Christina De Nicola of MLB.com reports.
The Marlins treated their final game before the All-Star break as a bullpen day, with Tyler Phillips starting and covering the opening frame before Petersen became the third reliever summoned into the contest. After entering with two outs in the top of the fourth, Petersen induced a Travis Bazzana popout to close out the inning. Petersen stayed in the game to begin the fifth and allowed a leadoff home run to Brayan Rocchio, then recorded two outs before exiting the contest after surrendering a base hit to Kahlil Watson. The right-hander may have tweaked the hamstring at some point during the matchup with Watson, but it's not yet known if the injury is severe enough to keep the reliever out following the All-Star break.