The Royals selected Maile's contract from Triple-A Omaha on Thursday.
Maile has spent the entire season in the minors up to this point, slashing .202/.324/.303 with two homers, nine RBI and 12 runs scored over 105 plate appearances. He'll now join the big-league roster to give the Royals some depth behind the plate while Salvador Perez sits out with a sore elbow. John Rave was sent down to Omaha to make room for Maile on the active roster, and Eric Cerantola was DFA'd to free up a 40-man spot.