Rooker was optioned to Triple-A Omaha by the Royals on Friday.
After recording a 1.026 OPS in Triple-A this season, Rooker slashed just .160/.276/.200 over 29 plate appearances once he joined the Royals. He will be sent down in order to open up a roster spot for Vinnie Pasquantino (shoulder) who is coming off the injured list.