Gsellman will shift back to a bullpen role beginning Sunday, Anthony DiComo of MLB.com reports.
Gsellman wasn't able to provide much length after his shift to the rotation, completing more than two innings just once in four starts. He'll serve in a multi-inning role out of the bullpen, though he isn't likely to get high-leverage work. Gsellman has an ugly 7.84 ERA and 2.13 WHIP through 10.1 frames this season.