Herget was optioned to Triple-A Louisville on Sunday.
Herget will return to Louisville just one day after he was called up. He appeared in the team's contest against the Cardinals on Saturday, allowing three runs on four hits while also hitting a batter over 1.1 frames. The 32-year-old was the odd man out in Cincinnati's bullpen with Casey Legumina (ankle) being activated from the 15-day injured list Sunday.