Bears defense looking to build momentum

Last week, Jarvis Jenkins had as many sacks in the second quarter (2) as he had in the other 35 games of his NFL career. But coach John Fox said he wasn't surprised.

"We don't hold 'em back," Fox joked. "They're free to go get the guy. I think a lot of it's a comfort level; knowing the defense. Guys can cut loose and not think, they're just playing and reacting."

The 6-foot-4, 315-pound Jenkins came to the Bears as an unrestricted free agent after four years in Washington, where he had a reputation as a stout run defender but not much of pass rusher, an area he sought to improve.

"In that position your fight's right in front of you," Fox said. "So the technique and quickness and recognition, converting run to pass and pass to run, is critical. He's just getting more comfortable in our system."

Jenkins credits work off the field during the week for the success the Bears defense is having.

"You could feel the confidence in the defense," Jenkins said of last week's first half in which the Bears allowed just 125 yards. "It all comes from film study. The preparation. Coach Fox said in the meeting that was our best preparation last week. We've just got to build on it. Going into the game knowing what you're going to get, you expect to make plays."

The Bears have allowed more points than any team in the league. But 2 kickoff-return touchdowns, an interception return for a TD and a 64-yard punt return that set up a field goal are responsible for a good chunk of that.

The defense is a much more respectable No. 11 in total yards allowed.

Hard lessons:

Much can be learned from adversity according to outside linebacker Lamarr Houston, who will see more playing time after the trade of Jared Allen.

"I think you see who's willing to work, and you find out who has character," Houston said. "Because everybody loves it when you're winning, and everybody's down when you're losing. You've got to see who's willing to work and who's working to get better every single day."

Lot of history:

Raiders head coach Jack Del Rio was John Fox's defensive coordinator when he was head coach with the Carolina Panthers and for the previous three years with the Denver Broncos.

In 2013, Del Rio filled in for Fox for the final seven games of the regular season when the head coach experienced a heart issue that necessitated an aortic valve replacement.

"He did a great job," Fox said. "He was the logical guy, being a head coach (with the Jacksonville Jaguars) before, and we had to make a decision on who would do that while I was recuperating.

"I go way back with Jack, been with him twice, and he did a great job in Jacksonville, so it's great to see he got another opportunity in Oakland."

Baby steps:

Veteran defensive lineman Jeremiah Ratliff is eligible to play against the Raiders after serving a three-game league suspension for a DUI conviction. But he's questionable because of a preseason ankle injury that limited his practice time last week.

"You definitely lose some conditioning," defensive coordinator Vic Fangio said, regarding the three weeks that Ratliff was inactive. "He wouldn't have played these first three games anyway, even if he wasn't suspended.

"It will be a chore for him to get back into playing shape. He probably will not be able to play as many plays (Sunday) as we would normally like."

The right mindset:

The trade of Jared Allen gives Sam Acho a promotion, and he will start at outside linebacker with Pernell McPhee.

"We came out the same year (2011), so it's been so cool to be able play with him," Acho said. "We talk all the time on and off the field. One thing I've learned from him is that any chance I get I have to go (all out).

"He talks about making up your mind. We have to make up our minds as a defense. What are we going to be as a defense. That's what you saw him do last week. He made up his mind, and you saw the performance. I'm joining him in making up my mind to change things."

McPhee had 2 sacks last week, 2 other quarterback hits and 7 tackles.

Getting his kicks:

Because of doubts that injured punter Pat O'Donnell will be able to kick Sunday due to an injured right knee, the Bears signed punter Spencer Lanning Saturday, two days after his tryout at Halas Hall.

Defensive tackle Brandon Dunn was waived to make room on the roster.

Lanning played in 32 games over two seasons (2013-14) with the Cleveland Browns, punting 177 times for 7,798 yards (44.1-yard gross average) and a 38.6-yard net average. He was originally signed by the Bears as an undrafted rookie in 2011 out of South Carolina.

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