Not only did the Chicago Bears lose quarterback Jay Cutler for likely four-to-six weeks due to a torn groin, but it was revealed on Monday that they also lost star weak side linebacker Lance Briggs for an estimated six weeks to a small fracture in his left shoulder.

When it rains, it pours in the injury department with the Bears over these last few years .

Briggs suffered the injury in the third quarter of the game as he tried to get by a block from Redskins tight end Logan Paulsen. It was reported that the seven-time Pro Bowl linebacker was 'probable' to return to the game, but he never did, and that's probably a good thing given that he had a fractured shoulder.

But Briggs' absence was most definitely felt by the Bears over the remainder of the game. Here's some eye-opening statistical proof:

And it was very clear while watching the game that Briggs was the best player on the field for the Bears before he left with the injury, recording eight tackles, one tackle for loss, and two pass deflections. Pro Football Focus gave him a +2.9 grade for the game (the highest Bears grade in that game from PFF on both sides of the ball).

The Bears are greatly struggling on defense, and the injuries that keep piling up to key players certainly aren't helping things (and the injuries without question have been a big factor in the defensive struggles).

In addition to losing Briggs until December (it appears), the Bears recently lost middle linebacker DJ Williams for the season due to a torn pectoral muscle, and defensive tackles Henry Melton and Nate Collins for the season due to torn ACLs. That's three starting players that have been lost for the season, and one in Briggs that will miss six weeks. Six weeks when the team could use him more than ever.

The 32-year-old has a team-leading 64 tackles and two sacks (and it's pathetic this is tied for the team lead through seven weeks, by the way) on the season.

For PFF's cumulative grading over the season (not including Monday night's Giants-Vikings game), the Bears' defense ranks 31st overall, 32nd against the run, and 29th in pass rush. Briggs has the Bears' highest cumulative PFF grade on defense (+2.5), their second-highest cumulative grade on run defense (+2.7), and their highest pass-rushing grade (+1.8).

To put it simply: One of the worst defenses in the NFL to this point, is losing their best defensive player to this point, and for an estimated six-week period while the defense is more depleted than it's been at any point this season.

Briggs has also been the defensive playcaller this season, a role he took over with Brian Urlacher's retirement in the offseason. And with Urlacher gone, Briggs has also become the leader of the defense. Just ask Bears cornerback Tim Jennings:

"I've seen Lance make so many great plays over the years," Bears cornerback Tim Jennings said. "We're going to miss him, but other people are going to have to step up. We all need to dig down deep and raise the level of our play with Lance out. He will always be the leader of this defense."
Source: ESPN Chicago

Now, veteran strong side linebacker James Anderson (who is in his first year as a Bear) will have to be the playcaller and leader of the linebacker corps at least, with rookie Jon Bostic manning the middle, and fellow rookie Khaseem Greene the most logical candidate to replace Briggs on the weak side. Bostic now has a whopping one start under his belt, and Greene has played a whopping one snap on defense.

Veteran Blake Costanzo is also a candidate to replace Briggs, but the 29-year-old is a career special teamer (where he's great though) and doesn't have the athleticism you're looking for in a starting NFL linebacker. Costanzo played 18 snaps on Sunday once Briggs went down, and came away with a -2.3 grade from PFF in that time.

The 6'1", 241-pound Greene was a fourth-round pick by the Bears in the 2013 draft after being the Big East Defensive Player of the Year and an All-American last year for Rutgers. Over his career at Rutgers, Greene forced an NCAA record 15 fumbles.

The way I see it, you know what you have in Costanzo, and it's a below average NFL linebacker with limited playmaking ability. Might as well see what you have in Greene, especially after you just invested a draft pick on him and hope he's a big part of the Bears' future. Try to get the inevitable youth movement going and get some valuable game time to evaluate Greene, especially alongside Bostic.

Also, we already know Greene's a better athlete than Costanzo and he clearly has a knack for taking the ball away from the offense. If your defense is going to struggle regardless as this one appears it will, give me the guy that may be able to at least make a game-changing play here and there.

Whatever the case, there's no doubt the Bears can't come close to truly replacing Briggs, and it's another brutal blow to a defense performing brutally on the field. Making matters worse, this defense won't have Cutler to bail them out on offense as he's already done a few times this season.

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