Dunning suffered a moderate elbow sprain during Saturday's start with Double-A Birmingham and will be placed on the minor-league disabled list.
The good news is that Dunning will not require a surgical procedure, but he will be shut for 6-to-8 weeks while undergoing a program consisting of rest and rehab. Following that timeline, he will begin a throwing program, so it's unlikely that the prospect will be back in action with Birmingham this season since the Rumble Ponies conclude their regular season Sept. 3 and the organization won't want to rush him back into action.