Buffalo Bills starting linebacker Kiko Alonso has torn the anterior crucicate ligament in his left knee and is expected to miss the entire National Football League season.

Alonso will be scheduled to have surgery, general manager Doug Whaley says in a statement released by the team Wednesday, a day after Alonso was hurt while working out in Oregon.

The injury to Alonso is a significant blow to the Bills before they even open training camp on July 20.

Alonso was an NFL defensive rookie of the year contender last season after being drafted in the second round out of Oregon.

He led Buffalo with 159 tackles, two fumble recoveries and tied for the team lead with four interceptions while barely missing a snap in playing all 16 games.