By Dan Durkin–

(CBS) After their Monday night comeback win against the Chargers in San Diego, the Bears (3-5) are on the road again to play the Rams (4-4) this Sunday.

The Rams play a physical brand of football and pose a huge challenge for the Bears on both sides of the ball.

Here are some areas of the game to focus on during Sunday’s tilt in St. Louis.

What to watch for when the Bears have the ball

Preparing for pressure

The Rams rank second in the league with 27 sacks and bring pressure from all three levels. Of those 27 sacks, 19 have come from defensive linemen, five from the secondary and three from linebackers. As a unit, they haven’t allowed a passing touchdown since Week 5.

Defensive coordinator Gregg Williams has one of the league’s most dominant defensive fronts — and certainly the league’s best defensive tackle in Aaron Donald — so it’s really unecessary to deploy a pressure-based scheme. However, that’s simply in Williams’ DNA. He uses the extra attention paid to the defensive line to get free runners to the quarterback.

The Rams have an athletic back seven, which allows Williams to play pre-snap games with his safeties and rotate them post-snap to give fuzzy pictures to the opposing quarterback. He frequently sends pressure from the slot in six- and seven-man pressure packages to choke out a quarterback’s escape routes as the pocket is collapsing.

Last week, the Rams were without defensive ends Chris Long (knee) and Robert Quinn (knee) as well as strong safety T.J. McDonald (foot). This week, they’re likely to get Quinn and McDonald back into the mix, which will allow Williams to run his preferred big nickel (three-safety) base package.

The Bears may need to counter with seven- and even eight-man (max) protection schemes early, as the Rams frequently bring no fewer than five rushers in obvious passing situations.

North-south running game

In their win over St. Louis last week, the Vikings had success attacking the middle of the Rams defense with zone, gap and isolation runs. Granted, Adrian Peterson is arguably the league’s best running back, but the approach made sense. Rather than try and outrun the speedy Rams defense to the perimeter, the Vikings neutralized their foe’s speed by attacking straight ahead and using the snap count to get movement along the defensive line.

Bears running back Matt Forte (knee) practiced in a limited basis Wednesday, but his status remains up in the air for Sunday. Rookie Jeremy Langford shined in Forte’s place as the featured back, and several of his successful runs came inside off of zone-read and inside-zone plays.

Each week this season, offensive coordinator Adam Gase has tailored a game plan unique for that week’s opponent. He’s been particularly creative with his running schemes.

Against the Chargers, the Bears had success using move tight end Zach Miller as the lead back in an I-formation on isolation plays. Look for the Bears to deploy their heavy (three-tight end) personnel groupings early on both for the run game — as well as extra protection in the passing game — to try and establish the line of scrimmage.

What to watch for when the Rams have the ball

Misdirection plays

The Rams’ passing offense is starved for targets, and quarterback Nick Foles leaves a lot to be desired in the pocket. He lacks awareness and mobility, and his accuracy wanes on throws to all three levels. The Rams rank last in the league in passing offense, throwing for a mere 177 yards per game on average.

Consequently, the Rams are a run-first offense — they run the ball on 50 percent of their plays, second-highest in the league — built around rookie phenom Todd Gurley. Off of the zone, gap and isolation runs they execute with Gurley, offensive coordinator Frank Cignetti has made misdirection plays a part of his base offense.

Next to Gurley, the Rams’ second-best player on offense is shifty and quick as a hiccup receiver Tavon Austin. The Rams run a variety of fly sweeps, jet sweeps, ghost motion and end-arounds with Austin.

On the sweep package, the goal is simply to get the ball into Austin’s hands as quickly as possible while he’s running at full speed and the defense is just getting off the snap. Austin is dangerous on the perimeter and a gifted open-field runner who’s averaging more than eight yards a carry and has two rushing touchdowns.

The Rams also use play-action off of their end-around package to get the ball deeper down the field. Not only is this a natural variation to the scheme, it’s also out of necessity. They must scheme to buy Foles time in the pocket so he can get the ball deep down the field.

The Bears’ back seven on defense must be extremely disciplined with their eyes and play contain rules, as Austin’s open-field speed is second to none and can lead to explosive gains.

Crowding the box

Gurley has quickly established himself as one of the league’s premier running backs. What’s scary is he’s not even fully recovered from the ACL injury he suffered nearly a year ago to the day against Auburn.

Gurley’s a unique prospect in the mold of Adrian Peterson who can bully his way through tight spaces and arm tackles, then has the extra gear to get to the second level and outrun the defense.

Given the Rams’ passing game struggles — Foles hasn’t thrown for more than 200 yards since opening week and has one multi-passing touchdown game — the Bears are going to see a heavy dose of Gurley.

Bears defensive coordinator Vic Fangio will likely play Adrian Amos in single-high looks and drop safety Antrel Rolle into the box as the eighth run defender. Last week against the Chargers, the Bears showed a lot of pre-snap split safety looks, only to drop Rolle into the box at the snap to fill a gap in run support.

It will be crucial for the Bears to not only know and fit their gap assignments, but they must gang tackle and rally to the ball against Gurley. He aggressively finishes his runs, which typically leads to extra yardage when he’s not wrapped up.

Dan Durkin covers the Bears for CBSChicago.com and is a frequent contributor to 670 The Score. Follow him on Twitter @djdurkin.