Herget was called up from Triple-A Louisville on Monday.
Hergert was added to the 40-man roster in November and is set for his major-league debut after posting a 3.58 ERA, 1.45 WHIP and 44:24 K:BB over 37.2 innings at Louisville. The 25-year-old figures to fill a low-leverage bullpen role for the Reds.