The Pirates placed Holderman on the 15-day injured list Thursday with a right wrist sprain, Noah Hiles of the Pittsburgh Post-Gazette reports.
It's unclear when Holderman was injured, but it perhaps at least partly explains a 16.62 ERA over his last five appearances. How long he might be sidelined isn't known at this point. Ben Heller was called up from Triple-A Indianapolis to take Heller's spot in the Pittsburgh bullpen.