The Royals also recalled outfielder Reymond Fuentes and right-handed pitcher Peter Moylan and optioned righty Dillon Gee to Omaha.
Fuentes, 25, began the year in the big leagues, batting .238 with three RBIs in six games. He was hitting .302 with two doubles and six stolen bases through 17 games at Omaha.
Moylan also had a stint with the Royals earlier this season. The 37-year-old went 2-0 with a 2.45 ERA through 7 1/3 innings of relief before being optioned back to the Minors on Sunday. Eibner's injury allowed the Royals to bring him back to the Majors before his 10-day waiting period expired.