By Jeff Joniak-

(CBS) The Bears host the Bills on Sunday at Soldier Field. Here are some keys for Chicago.

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Offense

Nothing matters more in the Bears’ offensive scheme than protecting Jay Cutler. It’s preached consistently by coach Marc Trestman. Forty-six of Buffalo’s franchise-record 57 sacks last season came from its defensive line, including 13 from Pro Bowl left end Mario Williams, whom Jordan Mills has to deal with after offseason foot surgery. Another 10 came from Pro Bowl nose tackle Kyle Williams. Another 10 came from developing end Jerry Hughes, and defensive tackle Marcel Dareus was named to the Pro Bowl and piled up 7.5 sacks. They did all this under then-defensive coordinator Mike Pettine, now Cleveland’s coach. His replacement is Jim Schwartz, the former Lions coach who knows the Bears well and who will have some attack points. The Bills also drew the third-most holding penalties in the league and were fifth in quarterback knockdowns. They make it tough to complete passes, and last season opposing quarterbacks had the lowest completion percentage in the league against the Bills, who also swiped 23 passes. However, leading tackler Kiko Alonso is out for the season, and Pro Bowl safety Jairus Byrd left for New Orleans. Protecting Cutler is the first priority, but running the ball will take the edge off of the Bills’ pass rush. They weren’t as dominant stopping the run last season.

Defense

Health, talent, experience and an infusion of youth fuels a remodeled Bears defense promising its share of new wrinkles. However, this group needs to come together quickly to stop the run. Gouged last season, they have to resolve the issue immediately against Buffalo. It’s a difficult ground game to prepare for, given the variety of options. The Bills led the NFL in rushing attempts and finished second behind the Eagles in yards. Elusive and speedy C.J. Spiller shares carries with trusted veteran Fred Jackson. Former 49ers fullback Anthony Dixon is in the mix for short yardage, where the Bills struggled last season. Bryce Brown is a dangerous big back with speed, and he gashed the Bears last December as a member of the Eagles. These four backs run behind an offensive line that averages 6-foot-6, 326 pounds. No team ran the ball more on first down last season than the Bills at 63.9 percent under coordinator Nathanial Hackett. His second-year quarterback, EJ Manuel, struggles with accuracy and decision making and last season averaged less than 5.5 yards per attempt, which ranked 29th in the league. Drafting playmaker Sammy Watkins and acquiring Mike Williams in an April trade with Tampa gives Manuel more options, but this team is all about running the rock.

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Special teams

With the exception of standout kicker Robbie Gould and a few other veterans, the Bears special teams unit has a massive infusion of new players. It’s a speedy group, and with veterans expected to fill roles on some units, the experience level is steady. It just has to come together. Jeremy Cain replaces Pat Mannelly as the long snapper, and rookie Pat O’Donnell handles the punting chores. The return game will start with Micheal Spurlock on punts, with Santonio Holmes possibly getting a turn or two and undrafted rookie Senorise Perry on kick returns. Buffalo is also going with a young punter in Colton Schmidt, replacing 15-year veteran Brian Moorman. Dan Carpenter is solid as the field goal kicker, with 33 made a year ago, fifth-most in the NFL. The Bills’ return game struggled last season, finishing 29th on kickoffs and punt return average. Still, Spiller might be in the mix to return kicks, and he had seven return touchdowns at Clemson. Avoiding field position-wrecking penalties and game changing turnovers will be the week 1 key here for the Bears.

Intangibles

Opening at home is an immediate advantage the Bears hope to seize upon. Advantages other than talent or creating mismatches are muted some in Week 1, where many surprises occur. Changes in scheme aren’t on tape yet, so really no one knows what’s coming. There’s are no trends to be found. Getting on the Bills quickly would be the way to go for the Bears. Last season, Buffalo was was winless in the six games it trailed at the half on the road under coach Doug Marrone. Given their desire to run the ball, playing catch-up isn’t in their best interest for the Bills, certainly not with a quarterback that is still young and developing in Manuel. The Bills were one of only three teams that kicked more field goals than scored touchdowns last season. The Bears hope to keep it that way. Discipline in all phases by Chicago is arguably the biggest overall key for this game.

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Jeff Joniak is the play-by-play announcer for the Bears broadcasts on WBBM Newsradio 780. Follow him on Twitter @JeffJoniak.