1) LeSean McCoy and the Return of Lance Briggs?
McCoy is having an excellent season, and the league's leading rushing attack takes on the league's worst run defense. You may have heard something about that. Lance Briggs has been cleared by the team and may play, but I'm not sure how much of an effect that'll have immediately. Not playing in seven games builds up a lot of rust, and especially with a shoulder that may not be 100%, we'll see if it affects his tackling. Still probably better than Khaseem Greene on the field at this point and his presence will at least push Jon Bostic off the field on third down.
2) Safeties vs DeSean Jackson
Jackson's been an interesting case this season. He's having the best year of his career, but it's largely been built on boom and bust. He's had three games this year of 150+ receiving yards (and one other 100-yard game). The thing is, he's coming off one such game (10 receptions, 195 yards) and on the year still gets 17 yards per reception. Jackson's still a big-play threat and deep threat, and he's already set a career high in receptions. This game depends a lot on Chris Conte and Major Wright making plays as the last line of defense.
3) Nick Foles
Foles has had a great year himself - he didn't throw his first interception this season until two weeks ago, then doubled his season total with one last week against the Vikings. And since he took over starting duties, he's only posted two games with a sub-100 quarterback rating. Foles has shown a pretty good tendency to spread the ball around to the targets at his disposal (just look at Riley Cooper's stats since Foles took over), and he hasn't had to do a lot more than find the open man when McCoy's been as lights-out as he's been, but could the two interceptions be the start of a regression to the mean?
4) Zack Ertz
Yeah, I'm listing a rookie tight end as a key. And the reason for that is he's been getting mixed into the offense a lot more frequently. He's had five receptions in three of his last six games, and that includes being held without a catch against the Lions and Packers. Over his last six games, he's got 18 receptions with 4 touchdowns.
Last week's contest against the Vikings was the only time the Eagles got less than two takeaways in their last six games. They have a takeaway streak that extends back to week 5. Protecting the ball is paramount this week; the Eagles offense is dangerous enough without being given a head start.
6) Long Drives and Points on the Board
Despite anything you may have heard this week, this game is about offense and slowing down the Eagles' offense - wait, that's what's been discussed all week? Well then.
This is one of those times where keeping the other team's offense off the field is a good idea (sounds like about every week with the Bears this year...). Keeping the ball moving and limiting the amount of time the Eagles' offense is on the field will help. But more importantly, the Bears have to put points on the board when they have the opportunity to.