Texas placed Gray on the 15-day injured list Monday due to right elbow inflammation.
The 31-year-old has struggled over his last 15 appearances out of the Texas bullpen, registering a 5.17 ERA, 1.40 WHIP and 16:4 K:BB through 15.2 innings. The Rangers recalled Robby Ahlstrom from Triple-A Round Rock to replace Gray in the bullpen and on the 26-man active roster.