The Royals selected Kudrna's contract from Triple-A Omaha on Tuesday, Anne Rogers of MLB.com reports.
The 22-year-old righty spent most of last season at Double-A Northwest Arkansas, where he had a 4.21 ERA over 94 innings. Kudrna made four appearances for Omaha late in the season and struggled at the highest level of the minors with a 14.29 ERA.