Stephenson will get the start for the Reds on Wednesday against the Mets, Mark Sheldon of MLB.com reports.
Stephenson has really pulled it together at Triple-A Louisville, posting a 2.87 ERA, 1.16 WHIP and 135 strikeouts in 113 innings. He has walked 57 batters, but that walk rate generally has been lower lately. He takes the spot vacated by Tyler Mahle, but it's uncertain if he'll get more starts beyond that, as it gives the Reds six starters again.