Warren (forearm) will begin a rehab assignment with Single-A St. Lucie on Tuesday, Anthony DiComo of MLB.com reports.
Warren has been cleared to test things out in games after missing the past three weeks of action with a right forearm strain. He'd been effective before getting hurt, holding a 2.45 ERA and 36:16 K:BB over 33 innings. Warren shouldn't need too many rehab outings before being reinstated to the active roster.