When the Bears travel to Philadelphia to take on the Eagles Sunday, keep an eye on these three matchups:

Bears linebacker Danny Trevathan vs. Eagles running back Jordan Howard

Trevathan has been among the most consistent players on the Bears defense, and with a rejuvenated Roquan Smith at his side, he might be the Bears' most crucial cog in stopping the run.

Last week, Trevathan picked up six tackles as the Bears held the Chargers to under 36 yards rushing and forced five three-and-outs. Trevathan leads the Bears in tackles this season, 45 solo and 61 total. As inside linebacker coach Mark DeLeone said last month, Trevathan is just really good at finding the ball and tackling the guy who's holding it.

This week, the inside linebacker will take aim at former teammate Howard. The Eagles fed Howard a season-high 23 times against the Buffalo Bills last week, and Howard picked up 96 yards and a touchdown. It won't be news to Bears fans that Howard can be a tremendous workhorse, as he rushed for 3,370 yards in his three seasons with the Bears.

The Eagles use Howard sparingly. Excluding the Bills game, Howard has averaged 11 carries a game and has only been targeted 13 times as a receiver. Eagles coach Doug Pederson runs a relatively similar offense to Matt Nagy and uses running back Miles Sanders in a similar fashion to the way the Bears use Tarik Cohen, splitting his touches between runs and passes.

If the Bears can shut down Howard and force the Eagles to go pass-heavy, they open up the opportunity for more sacks from Khalil Mack and more interceptions from their stacked secondary.

Bears cornerback Kyle Fuller vs. Eagles receiver Alshon Jeffery

The Eagles, like the Bears, discovered the virtue of a run-heavy offense last week.

However, the Eagles, like the Bears, would be a pass-centric attack, if they had their druthers. Quarterback Carson Wentz will look to get tight end Zach Ertz involved, and the Bears will likely use a combination of linebackers and safeties to cover one of the most prolific tight ends in the NFL. 

Outside, however, we're likely to see a decent amount of one-on-one action between another pair of former teammates, Fuller and Jeffery. 

Jeffery, who spent his first five NFL seasons in Chicago, is currently the Eagles' top receiver. While he doesn't see the volume of throws he once knew during his time under Marc Trestman, he remains a matchup issue out wide. Jeffery has 30 receptions for 317 yards and three touchdowns this season. 

Fuller snagged his third interception of the season, the third time in his career he's crossed that mark in a single season. Earlier in the week, Eddie Jackson said that the defense needed to create more turnovers and put more points on the board. No one has more potential in that regard than Fuller.

Bears guard Cody Whitehair vs. Eagles defensive tackle Fletcher Cox

While the Bears were finding their rushing attack against the Chargers, the Eagles were limiting the Bills' ample rushing options: quarterback Josh Allen and running backs Frank Gore and Devin Singletary combined for 98 yards. 

Much of the credit goes to the play of the All-Pro nose tackle Cox.

Cox had 10.5 sacks last season and has 2.5 in the past two weeks, but as a defensive tackle, he can be measured not just by the plays he makes but also by the resources opposing offenses have to dedicate to stopping him.

This season has been one of transition for Whitehair. He's moved from center, where he played for three seasons, to guard. He signed an extension in the days before the season opener, officially moving him from a young gun to a franchise cornerstone. Still, as the Bears dabble in a more run heavy-offense, they are going to need Whitehair to win one-on-one battles with Cox to allow James Daniels and a blocking back to get downfield to attack the second level.

Nagy acknowledged that his linemen were pleased to see more downhill running work its way into the game plan.

"There's a lot of that just because there's some concepts in the run game you can get to in the I-formation, where it's just a lot of downhill running, which is great," said Nagy. "When you do that, you've got to be able to win your one-on-one battles. You've got to be able to win double-teams. You've got to be able to get to second level."