"We're waiting for the swelling to go down. His vision is good and everything seems fine," said Royals assistant general manager J.J. Picollo.
This is the second injury for Colon this season. A toe injury sustained in a play at home plate while he was with Double-A Northwest Arkansas kept him out of the lineup for about a month.
Colon was playing shortstop and second base for Omaha and was 7-for-17 (.412) in five games. He hit .289 in 73 games at the Double-A level.