Mahle struggled in his last outing against the Phillies, completing just one inning and allowing three runs on six hits with three strikeouts and a walk. The righty has lasted less than six innings in five of his last six starts.
Scherzer faces the Reds for the first time since Opening Day, when he struck out 10 in six shutout innings. He was dominant in his last start as well, with 11 strikeouts in eight innings against the Marlins, yielding only an unearned run.