Petty (undisclosed) will start for Triple-A Louisville on Thursday.
Petty failed to make the Reds' roster out of spring training and spent some time on the injured list with an undisclosed issue. He's made four starts for Louisville, posting a 6.61 ERA, 1.41 WHIP and 22:5 K:BB across 16.1 innings. The 23-year-old made his MLB debut last season, pitching in three games with Cincinnati and allowing 14 runs (13 earned) on 14 hits and eight walks with seven strikeouts across six innings.