The Chicago Bears made a massive swing on Thursday, trading for All-Pro defensive tackle Jeffrey Simmons, widely viewed as one of the best defensive tackles in the NFL, if not the best. The move came at a steep cost. Chicago parted ways with two first-round picks and a fourth-round pick to get the deal done.

You can debate the pros and cons of that price all day. However, the deal is done and Simmons is a Bear. He could make his debut as early as Monday night against the Seattle Seahawks, and he should be an immediate difference maker for defensive coordinator Dennis Allen’s unit.

So what does Simmons’ arrival mean for this defense? How will Allen deploy him, and what does it mean for the rest of the room?

Bears defense has bright spots, but also some concerns after the first seven games

The Bears made considerable additions to the defense this offseason, and several of them have delivered. Rookies Dillon Thieneman at safety and Malik Muhammad at cornerback have been bright spots. Linebacker Devin Bush, one of the prized free agents, has played at a high level in his role. Chicago is also hoping for a late-season return from safety Coby Bryant, the top free agent addition, which would give the back end another boost.

Unfortunately, the rest of the defense has struggled. Cornerback Jaylon Johnson has taken a step back on the outside, and Tyrique Stevenson has been a liability in coverage. Even Thieneman has had his share of rookie issues. And the defensive line has been inconsistent at best, which is a big reason this trade happened in the first place.

Still, the run defense has improved significantly from last year. The Bears rank third in the NFL in rushing yards allowed per game at 87.6, and Simmons will only boost that as he ranks second among all interior defensive linemen with 15 run stops. Allen’s defense is an attacking, downhill unit against the run. Simmons’ ability to collapse the interior will let linebackers Bush, D’Marco Jackson, and a returning T.J. Edwards see and hit those holes even more aggressively.

Jeffrey Simmons fixes the pass rush problem that has exposed Chicago’s secondary

In the passing game, Allen’s scheme is exotic and leans heavily on press-man coverage, pairing the pass rush with the coverage behind it. That only works if the rush gets home consistently, and that frankly hasn’t been the case.

That’s where Simmons comes in. Simmons ranks in the top five in pressures among interior defensive linemen and has four sacks. That total would already tie nickel cornerback Kyler Gordon for the team lead.

Speaking of, Gordon has piled up all four of his sacks over the last two weeks since returning, and he’s been a major difference-maker. The nickel spot is the chess piece of this defense, with Gordon being a player who can drop into coverage or blitz and help disguise Allen’s looks.

The problem is the Bears have been over-reliant on Gordon as a blitzer since his return because the front four can’t generate pressure on their own, particularly on the interior. Jarrett has been much improved now that he’s healthy and leads the interior with 15 pressures and a 13.8% pass rush win rate, but he hasn’t recorded a sack. Meanwhile, Neville Gallimore, Jordan van den Berg, and Kentavius Street have combined for seven pressures all season. All three sit below an 8% win rate, and two of them are under 5%.

Dayo Odeyingbo was another bright spot with 14 pressures, three sacks, and an 11.1% win rate before landing on injured reserve. Once he returns, he’ll give Chicago another situational option. For now, Jarrett and Simmons will be the starting duo inside.

That pairing should give Allen the interior push he has been missing. More consistent pressure from four rushers also means Gordon can spend more time in coverage, where his speed helps the team match up with faster receivers, instead of leaning heavily on him as a blitzer. However, it’s still an option Allen can sprinkle in with how effective Gordon has been rushing the quarterback.

Montez Sweat could be the biggest beneficiary

Then there’s Montez Sweat. The Bears didn’t get great pass rush returns from Sweat over the first five games before his two-game suspension, and he left a lot of meat on the bone. On the other side, Austin Booker hasn’t been consistent either. Daniel Hardy showed promise during Sweat’s suspension and earned praise from Bears coach Ben Johnson. Shemar Turner also gives Chicago another body to rotate off the edge.

Sweat’s return is the big one, though, with Simmons now in the picture as well. This is a player who had 10 sacks last season. With offenses forced to double-team Simmons next to Jarrett, Sweat and Booker should see far more one-on-one opportunities. Winning those matchups is a must.

“I think we’re going to continue to challenge him,” head coach Ben Johnson said of Sweat. “How much more can we affect the passer when he does get one-on-one situations? I know there’s a number of times when you’re perceived as the premier pass rusher on your team that either they’re sliding the protection your way or you’re getting all the chips and the nudges, and so that does take a toll.”

When the front four can’t win, the Bears have had to send extra rushers from the nickel, safety, or linebacker spots. That leaves one fewer defender in coverage, and when those blitzes don’t hit, the secondary has been getting exposed.

That’s why this trade speaks volumes about where Chicago believes its defense can go. Simmons gives the Bears a player who can help the unit win with the front four, letting Allen get more creative with his other pieces, and strengthening an already solid run defense. The impact should show up right away.