Gray left Friday's game against the Athletics with right elbow soreness and tightness in his forearm, Patrick Saunders of The Denver Post reports.
Gray allowed five runs on four hits and two walks in 2.1 innings prior to his departure, and manager Bud Black said that the right-hander's injury contributed to his lackluster performance. The severity of the issue isn't yet known, but Gray's status will become clearer after further testing.