The Reds optioned Richardson to Triple-A Louisville on Thursday.
Richardson will be sent down to the minors alongside Yosver Zulueta in order to make room on the active roster for Graham Ashcraft (forearm) and Chase Burns (elbow), both of whom returned from the injured list Thursday. Richardson, 25, surrendered three earned runs in one inning during his lone appearance since being promoted Sept. 3 and now carries a 4.54 ERA and 1.54 WHIP through 37.2 MLB frames.