Clarke will serve as the Diamondbacks' opening pitcher in Wednesday's contest against the Phillies.
Clarke, who holds a 2.60 ERA and 37:11 K:BB over 62.1 innings this season, will be making his first big-league start since 2023. He'll likely cover the opening frame or two before giving way to right-hander Jose Cabrera, who is expected to absorb most of the innings as a bulk reliever.