Bears confident vs. Tim Tebow

LAKE FOREST, Ill. -- The last mobile quarterback to inflict damage on the Chicago Bears' defense was Carolina Panthers rookie Cam Newton, who rushed for two touchdowns, passed for another and compiled 409 total yards of offense in a losing Week 4 effort.

Newton generated those numbers in an offensive system that slightly mirrors what the Bears are expected to see from Denver this weekend in the Mile High City.

But with one major difference.

"Nothing against [Tim] Tebow, but Cam Newton is a better athlete, he's faster," Bears perennial Pro Bowl linebacker Lance Briggs said on Thursday.

"Carolina, they do some of the same things, but Cam Newton is a little faster. Teams do it [a spread offense], they just don't live and die by it like Denver."

Nor is Tebow comparable to Eagles scrambler Michael Vick, according to fellow linebacker Brian Urlacher. The Bears limited Vick to a mere 34 yards rushing and zero touchdown passes in a victory over Philadelphia on Nov. 7.

"He's not Michael Vick," Urlacher explained. "We're an athletic defense, we got a pretty good front seven or eight and we run to the football. Hopefully we get some takeaways, which we haven't done the past couple of weeks. Just run to the football and do what we do.

"We have rules for every offense we play that stay true for all season long. Carolina ran a similar offense, every once and awhile they run some option so it's not a [big] adjustment for us."

With Tebow at the helm, the Broncos have won five straight, six of their last seven and are currently tied with Oakland atop the AFC West, despite getting off to a 1-4 start. While Tebow only has a 47.5 completion percentage, the quarterback is averaging 5.7 yards per rushing attempt on 82 carries. He currently is the Broncos' second leading runner (468 yards) behind tailback Willis McGahee (886 yards).

The Denver quarterback has also done a remarkable job protecting the football, throwing one interception in 158 pass attempts.

"[He's a] scrambler ... they run him a lot ... he's one heck of a football player and we're going to have to stop that crap," Briggs said.

"You have to be disciplined, but we have the guys that can do it. It's not rocket science."

But what if Tebow does in fact lead the Broncos past the Bears on Sunday?

"I will be freaking [upset] but he's a competitor," Briggs said. "Of course, you don't want to lose ... we're in a position where we can't lose and every game is a must."

The Bears defense enters the weekend ranked No. 8 overall in rushing defense (99.8) and No. 9 in points allowed (20.2), which means something must give against the Broncos top-rated rushing offense.

"First things first, it's going to be a physical game," Briggs said. "That's right up our alley. I expect that after this game guys are going to need a lot of ice from both teams.

"When you know the other team is going to run the ball, you just know to get your chin strap strapped up and your big boy pads on because it's going to be physical."

Jeff Dickerson covers the Bears for ESPNChicago.com and ESPN 1000.