Corbin (elbow) is scheduled to throw five innings (75 pitches) Monday at extended spring training, Nick Piecoro of AZ Central Sports reports. Corbin will embark upon one of the most meaningful leaps in the rehab process, and if all goes well, he'll be cleared for a rehab outing at Double-A Mobile the following week. The Diamondbacks are tentatively targeting an early-June return for their former ace.