The Chicago Bears are transitioning to a 3-4 defense this season under coordinator Vic Fangio. The shift in scheme also requires a shift in personnel, as 4-3 defenders don’t often fit in 3-4 systems.
This is particularly true at defensive tackle.
Since 2004, the Bears have relied on smaller, faster defensive tackles. Under former head coaches Lovie Smith and Marc Trestman, DTs were asked to one-gap penetrate off the ball. Disruption in the backfield was critical to the success of Chicago’s interior defenders.
That’s not the case in 3-4 defenses, where defensive tackles, or nose tackles, are asked to occupy two gaps. Shooting gaps at nose tackle is a thing of the past. Fangio asks his beefy linemen to hold their ground, occupy blockers and allow the linebackers freedom to make plays.
GM Ryan Pace believes the Bears already have two legitimate nose tackles on the roster.
“I think there's a couple guys who can do it,” Pace said at the 2015 NFL Scouting Combine. “One of them has done it before in Dallas. It doesn't have to be this big, 350-pound space-eater. You can use him in a variety of ways.”
Ratliff is 32 and has played just 22 games the past three years combined. He can still be very productive – he had 6.5 sacks in 11 games last season – yet relying on him to suit up 16 games next season is downright foolish.
Ferguson has the size (6-3, 315) and strength to be effective at nose tackle but he’s still very raw, and he’ll now have to learn an entirely different set of techniques. That could take time.
If the Bears truly want to upgrade at defensive tackle, they’ll consider at least one of these established veterans in free agency.
**Editor's Note: For our purposes, we're only evaluating unrestricted free agents (UFAs).**
Ndamukong Suh (6-4, 305) Age: 28
Suh is one of the most disruptive defensive tackles in the league and will command a ridiculous salary, similar to the $100 million contract J.J. Watt signed last offseason. His impact would be huge but his questionable character, combined with his sky-high price tag, will likely push him off Chicago’s radar.
Terrance Knighton (6-3, 331) Age: 29
Knighton played the last two seasons in Denver under current Bears head coach John Fox. He’s a prototypical space-eater who excels in stuffing the run. Very few NFL interior defenders can occupy blockers like Knighton, who has missed just three games in his six-year career. He’s a productive veteran leader with experience under Fox, one who would perfectly fill Chicago’s need for a two-gap NT.
Jared Odrick (6-4, 304) Age: 27
Odrick is one of the better all-around defensive tackles in the game. He can collapse the pocket in the face of the quarterback – he had 18 hurries and 9 QB hits, per Pro Football Focus, despite recording just 1.0 sack last season – and he’s solid against the run. A five-year veteran whose played in every game the past four seasons, Odrick would be a quality acquisition.
Dan Williams (6-2, 327) Age: 28
In five seasons with the Cardinals, four as a starter, Williams has just 2.0 sacks. He's borderline worthless on passing downs but he's a rock against the run. His size and strength make him nearly impossible to move. He's one-dimensional but Williams would immediately provide a huge boost to Chicago's run defense, and will come cheaper than Knighton.
Ahtyba Rubin (6-2, 325) Age: 29
Rubin has been Cleveland's run-stopping nose tackle for seven seasons. Yet an ankle injury led to a very disappointing 2014 campaign. As such, Rubin could come at a discounted price. He provides little pass rush but he can occupy two gaps with the best of them.
B.J. Raji (6-2, 337) Age: 29
Look up "overrated" in the dictionary and you'll find a photo of Raji, who missed all of last season with a torn bicep. He's been a liability since his one good season in 2010, and he's expected to re-sign with the Packers. Moving on.
Kendall Langford (6-6, 313) Age: 29
Langford is decent, albeit unspectacular, and can play the nose tackle or defensive end. He still has a good year or two left in him, so he might be worth a small investment.
Barry Cofield (6-4, 303) Age: 31
Cofield is a Ratliff clone, both in size and relative production. In addition, he missed half of the 2014 campaign with an ankle injury, which severely limited him after returning to the field. He can still play but he's aging and coming off an injury. With Ratliff already on the roster, the Bears should look elsewhere.
Corey Peters (6-3, 305) Age: 27
Peters isn't a show stopper but he's a steady presence against the run who can provide occasional pressure on the quarterback - he had 5.0 sacks in 2013. Peters isn't a sexy pickup but he's young and productive, and would make a quality rotational defensive lineman, both at nose tackle and defensive end.
Pat Sims (6-2, 310) Age: 29
Sims can stuff the run but he's limited as a pass rusher (7.0 sacks in seven NFL seasons). He's an under-the-radar space-eater who could serve as a quality backup in the Windy City.
THE PICK: Dan Williams
Williams has ideal size for a 3-4 nose tackle and he's a load to move. He eats up space along the line of scrimmage and demands double teams at the point of attack. He would immediately elevate Chicago's run defense.
Williams comes off the field on passing downs, so he won't command a hefty contract like Knighton. With Williams inside, the Bears would be free to address their pass-rush needs in the draft.
Jeremy Stoltz is Publisher of BearReport.com and a member of the Pro Football Writers of America. He is in his fifth season covering the Chicago Bears full time. Follow Bear Report on Twitter.