The Reds optioned Petty to Triple-A Louisville on Thursday.
As expected, Petty will head back to Triple-A after he was designated as the Reds' 27th man for Wednesday's doubleheader with the Cardinals. He took the hill for Game 2 of the twin bill and was dealt a loss in his MLB debut after giving up nine earned runs on seven hits and two walks while striking out three batters over 2.1 innings.