The Royals recalled Zerpa from Triple-A Omaha on Saturday.
With Chris Stratton (forearm) headed for the injured list, the Royals will call upon Zerpa to help get their bullpen through the final couple weeks of the regular season. The 24-year-old southpaw owns a 4.40 ERA and 1.57 WHIP through 47 big-league innings on the year and will most likely serve in middle relief while with Kansas City.