LINCOLN, Neb. (AP) — Nebraska middle linebacker Michael Rose will undergo knee surgery next week, making him the third key member of the defense in three days to be ruled out for the season.

Coach Bo Pelini said Saturday that Rose injured his knee in a non-contact drill Friday.

Pelini announced Thursday that the Cornhuskers had lost nickel back Charles Jackson to a knee injury, and on Friday the Athletic Department announced that safety LeRoy Alexander would be suspended for the season.

Pelini said he’s confident the defense “will be just fine” because of the quality of players competing for open positions.