Kansas City, Mo. ? Kansas City, Mo. — Shortstop Mike Aviles, Kansas City’s player of the year last season, will undergo Tommy John surgery and be sidelined for up to 12 months.

Manager Trey Hillman said Wednesday that Aviles would have ligament replacement surgery on his right elbow on July 8, another blow to a team that has been hit hard by injuries.

After struggling through the minor leagues for seven years, Aviles was brought up from Triple-A last season and hit .325, tops among major-league rookies.