Cruz was placed on the 15-day injured list Sunday with a right shoulder strain, Sonja Chen of MLB.com reports.
Cruz has struggled out of the gate to the tune of a 6.59 ERA over 13.2 innings out of the bullpen, and he'll now be shut down for at least a couple of weeks because of the shoulder injury. The Reds reinstated Graham Ashcraft from the bereavement list in a corresponding move.