Gray will be shut down from throwing for 3-to-4 days after he was diagnosed Sunday with mid-back spasms, Mark Sheldon of MLB.com reports.
Gray described the back spasms as a recurring issue, so the Reds will let him take the next few days off with the hope that the respite will help resolve the matter. The right-hander said he expects that the shutdown period will put him behind the Reds' other starting pitchers about a week, which could result in beginning the season on the 10-day injured list. That said, Gray likely wouldn't miss more than one or two turns through the rotation, so fantasy managers shouldn't push him too far down their draft boards as a result of the injury.