Nebraska's Pelini plans to use bye week to tighten a defense that keeps giving up big numbers

Nebraska has a timely open date before it starts Big Ten play. It will be no vacation for the Cornhuskers' defense.

Masked by the margin of victory in Saturday's 59-20 win over South Dakota State was a defensive performance coach Bo Pelini called his team's worst of the season.

The Championship Subdivision Jackrabbits piled up 465 yards, including 202 on the ground by Zach Zenner. SDSU made 25 first downs and averaged 6.9 yards a play.

Pelini said part of the Huskers' problem is attitude. He's concerned that his players are too passive. He says they need to develop a "killer instinct" or it could be a tough season.