After learning that Henry Melton tore his ACL in the team's 40-23 victory over the Pittsburgh Steelers on Sunday, the Chicago Bears on Friday placed their franchise-tagged defensive tackle on Injured Reserve.

In a corresponding move, the Bears signed 27-year-old defensive tackle Landon Cohen (pictured above) to the 53-man roster. Cohen was among free-agent defensive tackles brought in for a Bears tryout at Halas Hall earlier in the week.

The 6'1", 300-pound Cohen has played in 27 career NFL games, with 20 of those fittingly coming against the Bears' week four opponent, the Detroit Lions. The Lions drafted Cohen in the seventh round of the 2008 draft, and he went on to start four of the 20 games he was active for on the team in 2008 and 2009. Overall, Cohen has 32 career tackles and no career sacks.

What's also notable about Cohen's Lions stint, is that Rod Marinelli was the head coach in Detroit at the time. Additionally, Cohen was active for two games this season with the Dallas Cowboys, and Marinelli is of course the defensive line coach for the Cowboys, after holding the same position for the Bears the previous four seasons. Cohen has also played for the New England Patriots (2010-2011), and the Jacksonville Jaguars, where current Bears defensive coordinator, Mel Tucker, served as the defensive coordinator.

Add all of that up, and you have to think that Cohen is very familiar with the principles of the Bears' defense.

25-year-old Nate Collins will move into the starting lineup with Melton out. Collins has shown some very good things in his playing time and in training camp, since signing with the Bears in 2012.

Collins played in nine games and 247 snaps for the Bears in 2012, and received a +4.9 grade from Pro Football Focus, the 30th-best grade for defensive tackles (and in the lowest amount of snaps for their 85 graded defensive tackles listed, so it's possible his grade could've been a bit higher with more playing time).

So far in 2013, Collins has a +0.6 from PFF, the fifth-best grade on the Bears' defense. It's worth mentioning that Henry Melton has the lowest grade for an NFL defensive tackle through three games, at -6.4. But Melton received a +15.8 grade in 2012, and it was assumed his play would get much better as the year went along, as he missed 99.9% of the preseason with a concussion.

Collins is expected to move into the starting nose tackle spot, where Stephen Paea (who has a very nice +4.1 grade from PFF this season) has been the starter, and Paea is expected to move into Melton's spot as the three-technique defensive tackle.

Melton's contributions (when on his game, of course) may not be able to be replaced as a pass-rusher, and that's of course the main area the Bears have struggled so far in 2013. So it's a big loss. However, I think Collins is a very capable starter and may even bring the Bears a more consistent, better overall game than Melton. Melton disappears some games and has always struggled against the run, whereas Collins has graded positively against the run over the last two years (+1.1 in 2012, +0.4 so far in 2013).

It's the depth at defensive tackle that is now definitely a concern for the Bears, and it's why they brought in Cohen, of course. Undrafted rookie free agent Zach Minter was arguably the biggest surprise to make the Bears' 53-man roster entering the season, and now he finds himself as likely the No. 3 traditional defensive tackle on the team. How many snaps he gets remain to be seen. Julius Peppers and Corey
Wootton will likely move inside to help try to generate a pass rush on passing downs, with Shea McClellin at defensive end.

Even though Cohen shouldn't take too long to figure out the Bears' defense, he hasn't practiced yet with the team, so he certainly won't be active on Sunday. It will be interesting to see if he's active against the New Orleans Saints in week four, but I would lean towards that not being the case.

Minter, however, should be expected to be active for the first time in his NFL career on Sunday.

UPDATE: So much for my Landon Cohen 'certainly won't be active on Sunday' stuff. In fact, he is active for the Bears' game against the Lions, and Zach Minter is not:
Contributing Source: ESPN Chicago

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