Analysis: Waldron has yet to resume a throwing program since suffering a left oblique strain while warming up in the bullpen March 14. He'll require more than the minimum 15 days to heal from the injury, and with Yu Darvish (elbow) joining him on the shelf to begin the season, the Padres will have room in the rotation for both Kyle Hart and Randy Vasquez, who had been competing with Waldron for the No. 5 starter role.