Chicago Bears 2015 Roster Turnover: Linebacker

Be sure to check out the full 2015 Roster Turnover Story Stream as I work my way through every position group for the Chicago Bears.

With the Bears making the switch to a 3-4 defense, their front 7 will look drastically different from the 2014 season. Defensive tackles will be on the nose or slide out to d-end, defensive ends will become outside linebackers or move closer to a 5-Technique DE and the linebackers will need to fit into one of 4 different categories.

For years, with their 4-3 base defense, Bears fans grew accustomed to seeing a middle linebacker (Mike), a weakside linebacker (Will) and a strongside linebacker (Sam), and those three positions still exist in a 3-4, but there will be an additional inside linebacker added to the mix, often times called the Jack.

Keep in mind that the 3-4 defense that Chicago defensive coordinator Vic Fangio has run in the past closely resembles a 4-3 in scheme, even though he runs it with 3-4 personnel. He often slid his 3 down linemen to the strong side, and walked his weakside OLB up to essentially be a defensive end. This was how Fangio used his 3-4 scheme to get a 4-3 Under look and probably also why head coach John Fox mentioned at his recent press conference that the Bears, "We're going to be a 3-4 terminology wise," rather than come right out and call his D a 3-4.

Before we get into the Roster Turnover at linebacker, let's go over some basic responsibilities of the four linebackers in Fangio's 3-4 defense.

The Will OLB is also called the Rush linebacker. In Fangio's defense the last few years, think Aldon Smith. He will flip from the right to the left from time to time, but when it's an obvious passing situation you'll usually find him on the right side of the D, ready to attack a quarterback's blind side.

The Sam OLB in a 3-4 is similar to what a Sam in a 4-3 does. He'll line up on the strong side of the formation, often taking on the block of the tight end, he'll have to cover the TE on occasion and he'll have some contain responsibilities. Since most offenses are right handed, he often lines up on the left side of the D.

Our sister site, Niners Nation, had a very good article last year about the inside linebacker responsibility in Fangio's San Francisco defense.

The responsibilities of the Mike and Jack ILBs differ from 3-4 to 3-4, but in Fangio's scheme the Mike plays more downhill as a run plugger, while the Jack is more flexible in terms of rushing the passer and dropping in coverage. Be sure to check out the Niners Nation article I linked above for a more detailed explanation.

Now onto the Bears' potential roster turnover...

Shea McClellin - signed through 2015 - Some people feel that McClellin is a perfect fit as a 3-4 Rush OLB and we may finally see him at that position.

When he was drafted I initially thought he was going to be a 4-3 Sam OLB that would occasionally rush the passer on 3rd downs. The Bears made him a 4-3 one gap defensive end and he didn't have the strength or technique to set the edge in the run game. He also struggled as a pass rusher with his counter moves, so it's safe to say his time at DE was a failure.

Which prompted the Bears to make him a linebacker.

He struggled with the transition, but I thought he played better as the season went on. Spending 2014 at linebacker will no doubt help his transition to the 3-4 this season, but I'm just not sure where he fits in. Head coach John Fox isn't sure where he'll play either, leaving the option open at all 4 LB spots. He has the athleticism to play anywhere, but I haven't seen the pass rush repertoire needed to be The Rush OLB.

Pro Football Focus had McClellin as one of the eight Bear defenders graded in the green (positive). They had him down for a +1.2 overall, but in the final 8 games of the season he was a +5.4.

Jon Bostic - signed through 2016 - Bostic has played both outside and in the middle for the Bears in his 2 year career, but the general consensus was his best fit was at OLB. He played inside linebacker in college in both a 30 front and a 40 front, and in the Bears' new 3-4 D, his best fit would inside as well. If he can get the coverage responsibilities down, he could play the Jack backer, but he does have the aggressiveness needed to be a run plugging Mike.

PFF had him at -1.0 in 2014 after having a -14.7 grade as a rookie. Bostic possesses the traits to be a successful NFL linebacker, he just has to put it all together. I'm excited to see how Bostic will fit in with the new D.

Lance Briggs - free agent - I know the popular opinion on Briggs is to let him walk, and odds are fairly high that's exactly what the Bears will do, but I think he could play in a 3-4 as an inside linebacker. Briggs only played in 8 games last season, one year removed from only playing in 9, but PFF had him down with a +7.6 overall grade in 2014. His high mark was in the run defense category (+8.6) and diagnosing a run play was always one of his strengths.

Wherever Briggs ends up in 2015, if he stays healthy, I think he'll be able to help a defense.

Christian Jones - signed through 2016 - For an undrafted free agent, Jones really looked like he belongs in the NFL. He had 2 sacks and he racked up 69 tackles while playing all 16 games (5 starts). He's 6'3", 240 pounds with good athleticism, and he played some MLB, OLB and DE at Florida State.

He has the size and skill set to play any linebacker position in Chicago's 3-4, and I think Vic Fangio will utilize his versatility. PFF gave him a -4.3 overall on the season at linebacker, but it was a terrible grade against the Saints (-5.4) that really did him in.

DeDe Lattimore - signed through 2016 - At South Florida Lattimore (6'0', 237 ) played both inside and outside linebacker, even rushing the quarterback on occasion, but he best projects to a 2 down inside linebacker in the NFL. He played in 10 regular season games for the Bears on special teams, and in the preseason he had 9 tackles in the finale against the Browns.

Khaseem Greene - signed through 2016 - Greene played the weakside linebacker position in Rutgers' Tampa 2 scheme, so he seemed like a natural fit when the Bears picked him in the 4th round of the 2013 draft. With the Bears going to a 3-4, I don't see where he fits in. He did improve his PFF grade from a -8.8 as a rookie, to a -3.0 last season.

Darryl Sharpton - free agent - Sharpton does have some experience playing as an ILB in a 3-4 defense, so if he checks out medically, I could see the Bears bringing him back on a small 1 year deal.

PFF had Sharpton down for 108 plays in 2014 with a -2.1 overall grade. Pass coverage was his poorest grade, as it has been most of his professional career.

D.J. Williams - free agent - I think the D.J. Williams experience is over for the Bears.

Jonathan Brown - signed through 2016 - Brown was signed to his reserve/futures deal by Phil Emery, so he may not fit the plans of the new regime. He's too short and too slow to play OLB in a 3-4 and he's probably not physical enough to play ILB.

2015 OUTLOOK - With a scheme change comes position changes and the Bears' initial plan is for defensive ends Jared Allen and Willie Young to become outside linebackers. Young probably won't be 100% til about July, but he'll probably play the same role in 2015 like he began the 2014 season, a pass rusher off the bench. Allen may be a sub package player as well, depending on free agency and the draft.

David Bass is another Chicago DE that will make the move to OLB, but I'm not sold on Lamarr Houston or Cornelius Washington transitioning to OLB. Houston did rush from a 2 point stance in Oakland and Washington did play a little 3-4 OLB in college, but I think both could stick at DE in Fangio's scheme.

The free agent market has a few options at both ILB and OLB. Fellow WCG writer Sam Householder has already touched on a couple of options in his free agency series.

Buffalo's Brandon Spikes is an experienced 3-4 inside linebacker and could serve as a 2 down thumper. David Harris, late of the Jets, is another experienced 3-4 ILB. Denver ILB Nate Irving may want to reunite with his old head coach John Fox.

As for the outside linebackers, New England's Akeem Ayers has 3-4 experience, as does Houston's Brooks Reed.

If the Bears are looking to draft some linebackers, and odds are that they are, we've been hitting on a lot of options in our Mocking The Mocks series that you can find in our NFL Draft section. OLBs Vic Beasley, Bud Dupree and Dante Fowler Jr. are three guys that could be in play at 7 overall.

Denzel Perryman and Benardrick McKinney are a couple of popular ILBs that we've talked about on WCG.

What are your thoughts about the linebacker position for the Bears in 2015?