The Rockies placed Gray on the 10-day injured list Wednesday with right forearm tightness, Patrick Saunders of The Denver Post reports.
After exiting his start against the Dodgers over the weekend with the forearm issue, the Rockies were initially optimistic that Gray wouldn't miss a turn through the rotation. His ability to complete a bullpen session Tuesday without incident seemingly backed up that sentiment, but Gray's forearm was evidently still bothering him a day after the workout, prompting the Rockies to deactivate him. Chi Chi Gonzalez, who has made 16 starts this season before recently shifting to the bullpen, likely represents the top candidate to step in to make a spot start for Gray in Thursday's home game against Atlanta.