Gregory played in one series of the Cornhuskers' 55-7 rout of Florida Atlantic last Saturday before leaving for the rest of the game. He spent the second half in street clothes with a brace on his knee and underwent a minor procedure on the knee Sunday morning.
"Something that flared up. I would say he's doubtful for this week. It's a knee issue," Pelini said to the Lincoln Journal Star. "We're not looking to rush him back right now."
Gregory had 10.5 sacks and 19 tackles for loss last season for Nebraska and was named to the preseason All-Big Ten team.
- Scooby Axson