Holmes (triceps) will make a second rehab appearance at Double-A Altoona on Thursday, Jason Mackey of the Pittsburgh Post-Gazette reports.
Holmes had been shut down for a little more than two weeks with right triceps inflammation before he was cleared to return to action with Altoona on Monday. He tossed two innings in that outing, giving up three runs on four hits and a walk. The Pirates' decision to let him make another appearance three days after he tossed 34 pitches suggests Holmes is progressing well and won't be in store for a lengthy rehab assignment.