Frost talks about Huskers needing a mental edge:  NU's secondary suffers a key injury

Scott Frost has the 24-hour rule. After a game is complete, the team has 24 hours to flush it out.

That rule was more challenging this week after a stinging 34-31 overtime loss at Colorado.

But junior offensive tackle Matt Farniok said the Huskers had one of their better Monday practices, and Frost agreed with that assessment.

That said, Frost was asked about what could have been nearly 48 hours after the Buffs rallied in Boulder.

"A lot of things stuck out," Frost said of watching back the film. "We got to have the right mentality coming out of halftime. If we score (in the) third quarter, the game is probably over."

After watching the film, Frost said fatigue was probably a factor. "We weren't playing as fast," he said.

Nebraska will have to put the loss quickly behind it. Northern Illinois (1-1) comes to town for Saturday's 7 p.m. contest. Frost said the Huskies are "like a swarm of bees or fire ants."

Other notes from Frost's Monday news conference:

* Frost confirmed that junior safety Deontai Williams is out for the "foreseeable future" after undergoing shoulder surgery. Williams hurt his shoulder in the season opener against South Alabama. Frost typically doesn't announce an injury unless it's season-ending.

* Wide receiver Kade Warner is close to returning, Frost said.

* Frost said the status of sophomore kicker Barret Pickering for Saturday's game is unknown. Pickering is dealing with a leg injury. Frost said senior Isaac Armstrong didn't know he was going to be the place-kicker at Colorado until last Thursday.

* Mohamed Barry asked about the Huskers' main goal still being in front of them: "Nobody’s going to care about Colorado when we’re in the Big Ten Championship. And that's a fact."