Merritt will serve as the Indians' 26th man for Saturday's doubleheader against the Tigers.
He has a 3.68 ERA, 1.33 WHIP and 66:22 K:BB in 80.2 innings at Triple-A Columbus this season. If Josh Tomlin or Carlos Carrasco gets into trouble early in their starts, Merritt, whose last start was June 24, will likely be called upon to eat some innings before heading back to Triple-A.