Richardson was optioned to Triple-A Louisville on Sunday.
The 23-year-old started for the past few turns through Cincinnati's rotation, but he'll head back to Triple-A after he posted a 7.90 ERA, 1.83 WHIP and 10:12 K:BB across 13.2 innings. Richardson should return to the rotation at Louisville, where he has a 3.60 ERA in three starts.