Holderman (wrist) will start a rehab assignment with Triple-A Indianapolis on Tuesday, Danny Demilio of PittsburghBaseballNow.com reports.
Holderman threw 22-to-25 pitches of live batting practice last Friday and will head to Indianapolis to begin what's expected to be a brief rehab assignment. The right-hander sprained his right wrist Aug. 8 and becomes eligible to return Friday.