Dunning left his start for Double-A Birmingham on Saturday with right elbow soreness, James Fegan of The Athletic Chicago reports.
This is obviously a troubling development for one of the White Sox's top prospects. Dunning will undergo an MRI in the next few days to determine the severity of the injury. Even if everything checks out OK, Dunning will likely be out for a while as the organization has every reason to be cautious. Dunning has posted a 2.71 ERA, a 1.18 WHIP and a 100:26 K:BB in 15 starts between High-A and Double-A this season.