The D-backs remain hopeful that Corbin (elbow) will be ready to return to their rotation by June, the Arizona Republic reports. Even though Corbin had Tommy John surgery in late March, the expectations from the team have consistently pointed to a return closer to 14 months than 12. The typical range is 12-to-18 months, and the D-backs lack pitching depth on the big league roster, so ensuring that Corbin is brought along carefully is easy to rationalize.