Gray was removed from Tuesday's start versus the Brewers with an apparent injury, Bobby Nightengale of The Cincinnati Enquirer reports.
The 31-year-old showed some discomfort while throwing his warmup pitches for the fourth inning, and he was pulled after receiving a look from the athletic trainer. Gray gave up two hits with five strikeouts and zero walks over three scoreless frames before being forced to exit due to the undisclosed issue.