Del Castillo (calf) will begin the season on the injured list, MLB.com reports.
Del Castillo reported to Diamondbacks camp with a left calf injury and didn't play in any Cactus League games, so it's not a surprise he's destined for the IL. It's unclear how far along he is in his rehab or how much time he might miss. Once healthy, Del Castillo could be assigned to Triple-A Reno.