The Royals optioned Erceg to Triple-A Omaha on Tuesday.
It's been a disastrous season for Erceg, who holds a 6.23 ERA, 1.89 WHIP and 31:29 K:BB over 43.1 innings. The Royals finally ran out of patience with the reliever after he recorded just one out combined over his last two appearances. His spot on the roster will be filled by Carlos Duran.