Clarke will serve as the opening pitcher in Saturday's game against the Padres, Jesse Friedman of GoPHNX.com reports.
Clarke gave up two earned runs in one inning during his last outing Thursday, but the D-backs will send him to the mound to begin Saturday's game as they attempt to sneak into the final wild-card spot in the National League. He'll likely remain on the bump for an inning or two before coming out of the game.