Bill Belichick gave his highest praise to new acquisition Jonathan Casillas on his morning conference call. He considers Casillas a "four down player." That's a term reserved for first round picks (Devin McCourty) and players who stick around for a long while (Rob Ninkovich, Kyle Arrington, Brandon Bolden). It means that Casillas has the skill set to play against the run, against the pass, and on special teams.
It means that Belichick thinks that Casillas can have an impact this season.
But how will that happen? The 6'1, 230 lbs linebacker isn't of the traditional Belichick-linebacker build. He's not 6'3, he's not 250 lbs, he's not a standard player you would see on a Patriots defense. He's a 4-3 outside linebacker who is best when used covering tight ends and running backs in the flat.
When looking at the Patriots current roster make-up, it's clear that they're not capable of a consistent 4-3 so long as Chandler Jones is recovering from a hip injury. Dominique Easley can play admirably at the defensive end spot, even if it's a complete misuse of his skill set, but it's clear the team's current defensive line is built on all of the 4-3 defensive tackles.
So how does Casillas fit into this four down mindset? First, the starters in the front seven- those who will dictate the defensive alignments- need to be noted. In reality, the only players who are on the field for the majority of the game are Dont'a Hightower and Rob Ninkovich, players who can succeed in both the 3-4 and the 4-3. Vince Wilfork is the next in line and, in the same vein, is multiple in his fronts.
There's Jamie Collins, who should be on the edge in either the 3-4 or the 4-3. Same with Akeem Ayers. The team views Easley as someone who can line up anywhere on the defensive line.
Main point? There is no defense. Chandler Jones is the only reason this team uses the 4-3 as its base set; without Jones, the team is just as likely to line up in the 4-3 and the 3-4. In reality, Ninkovich, Hightower, Collins, and Ayers are all edge players who can drop back into zone coverage, can stop the run, and can rush the passer. The team just chooses to play Hightower and Collins in the middle.
And this is where Casillas comes into play.
Collins shouldn't be in the middle. He was far better against the Bears than he was against the Jets, but he's imitating Hightower of 2013: an edge player out of position in the middle of the field due to injuries. The Patriots need to keep Collins on the outside edge of the defensive front and in a more comfortable position. I don't believe the trade for Casillas was to get Collins off of the field.
Instead, look for Casillas to complement Hightower in the middle of the field. Let Hightower thump and Casillas cover. Collins will be free to play on the outside in both the 3-4 and the 4-3, while Ayers can slide from 4-3 defensive end to 3-4 outside linebacker. Of course, Ninkovich can rotate with Ayers and Collins to keep fresh, especially as he's been looking particularly nicked up the past couple of weeks.
Easley, Wilfork, Casey Walker, and Chris Jones can all rotate as the defensive tackles in these fronts, too. In fact, they'll likely remain more fresh due to the rotation of players and defensive sets allowing them to have more rest on the sideline.
Don't expect Casillas to receive full snaps in his first game, but note that Ayers played 32 of 70 snaps against the Bears, or 42%, so the new linebacker should see a few snaps in his first game.
Here's my thoughts on the line-ups; how would you line them up?
3-4 Front: Easley/Jones-Walker-Wilfork; Collins-Hightower-Casillas-Ninkovich/Ayers
4-3 Front: Ayers-Easley-Wilfork-Ninkovich; Collins-Hightower-Casillas