Audibles: NFC North Week 1 preview

Posted by ESPN.com's Kevin Seifert

Detroit Lions at Atlanta Falcons, 1 p.m. ET

A certain buzz followed the Lions around Detroit this summer as fans wondered whether their wide receiver duo and new running game might actually propel the team to a winning season. No less important, however, has been a quieter effort to improve a run defense that has ranked in the bottom third of the NFL for the past three years.

Even after trading Pro Bowl defensive tackle Shaun Rogers, the Lions are hoping to bring a scrappier and more effective run defense to Atlanta this weekend. They'll need it, considering the Falcons intend to rely on new tailback Michael Turner and holdover Jerious Norwood while rookie quarterback Matt Ryan adjusts to the professional game.

Lions coach Rod Marinelli has signed a half-dozen players with ties to the Tampa Bay Buccaneers, where he spent 10 years as an assistant before joining the Lions. Veteran defensive tackle Chuck Darby is one of them, and Darby has been assigned the task of replacing Rogers.

But the Lions needed to make changes to the entire gut of their defense, not just at defensive tackle. Middle linebacker is of significant concern. Veteran Paris Lenon is holding down the position for now, but the Lions were hoping rookie Jordon Dizon would win the job so they could move Lenon to the outside. That development could occur later this season, but as of now the Lions don't have their ideal alignment in place.

Chicago Bears at Indianapolis Colts, 8:15 p.m. ET

This statistic bears repeating: The Bears' first-team defense gave up scores on seven of their final nine drives. (A blocked field goal accounted for one of the two non-scoring drives.) And this one is not too far behind: Overall, the Bears' starters and reserves combined to give up more yards per game -- 376 -- than any other NFL team.

You can't put too much stock in preseason statistics, but by any measure the Bears' defense wasn't an impressive group this summer. Certainly, it didn't resemble a defense than can carry a team, as appears to be the Bears' internal recipe considering their underwhelming personnel collection on offense.

No one has sugarcoated the situation. Coach Lovie Smith and defensive coordinator Bob Babich have expressed appropriate concern about effort level, gap control and tackling.

So the question Sunday night will be whether Brian Urlacher, Lance Briggs, Tommie Harris and company can turn on the light in time for the regular season. They won't have a lot of breathing room against the Colts' high-powered offense. Quarterback Peyton Manning missed the preseason after knee surgery, but we're guessing he was especially motivated to return for Week 1 after watching preseason video of the Bears.

Minnesota Vikings at Green Bay Packers, 7 p.m. ET Monday

The lights. A slightly inebriated crowd of 72,000. National television. Memories of Brett Favre.

There will be no shortage of pressure Monday night on new Green Bay Packers quarterback Aaron Rodgers. The Minnesota Vikings, however, want to place another burden at the top of the list: Their defense.

The Vikings acquired defensive end Jared Allen and safety Madieu Williams during the offseason with the goal of elevating their pass defense to a level approaching their already-suffocating run defense. Williams won't play Monday night because of a neck injury, but the Vikings still feel they have made significant strides against the pass this summer.

"There's going to be a lot of pressure [on Rodgers]," Vikings safety Darren Sharper said. "Not just him trying to replace a legend, but what we're going to apply to him. I'm not just saying that as far as talking trash. But playing against a team on Monday night, against a defense as good as ours, it's just going to be a different tone. ... We definitely want there to be some pressure, to get him flustered a little bit. It's going to be difficult [for Rodgers] -- besides the fact that he is replacing Brett and playing at home and all the expectations."