Petty will start the second game of Saturday's doubleheader versus the Cardinals, C. Trent Rosecrans of The Athletic reports.
The Reds and Cardinals have a twin bill Saturday after Friday's game was rained out, and Petty will be up to serve as the 27th man for Cincy. Petty made one spot start earlier this season, allowing three runs with a 1:2 K:BB over 5.2 innings. The righty holds a 6.32 ERA and 31:15 K:BB across 31.1 frames covering eight starts with Triple-A Louisville this season.