Michigan State's Williamson has surgery on bicep
The fourth-ranked Spartans have had to deal with several major injuries this season. Linebacker Ed Davis, defensive back Vayante Copeland and offensive lineman Dennis Finley are out for the season, and offensive lineman Jack Conklin and tight end Josiah Price also went down with injuries recently.
Williamson, a fifth-year senior, has intercepted two passes this season.
Michigan State plays at Rutgers on Saturday night.