Triple-A Durham reinstated Sterner (undisclosed) from the 7-day injured list Thursday.
Sterner went about one month between appearances due to an unspecified injury, though he looked electric in his first game back Friday against Triple-A Columbus. The 28-year-old right-hander fanned three batters in a perfect inning and now owns a 3.67 ERA with 48 strikeouts across 41.2 frames this season with Durham.