After a season in which the Green Bay Packers finished dead last in the NFL in total defense and gave up the most passing yards in league history, something has to change, right?

The Packers couldn't maintain the status quo. They have one of the most dangerous offenses in the NFL and have a roster stocked with some of the most talent in all of professional football. The window is open for them to be Super Bowl contenders for the next several seasons.

So for the first time since 2006 when they signed cornerback Charles Woodson and defensive lineman Ryan Pickett, the Packers are getting heavily involved in free agency.

In addition to adding center Jeff Saturday, the Packers appear to be attempting to bolster their pass rush. They reportedly signed Tony Hargrove on Thursday and Daniel Muir the week before. And they've got Dave Tollefson in for a free agent visit as of yesterday.

The names of those defensive players got me curious, however. They didn't seem like they fit the prototype the Packers look for in defensive coordinator Dom Capers' 3-4 system.

Hargrove's strength seems to be as a one-gap penetrator, whereas the Packers typically ask their defensive linemen to be two-gap read-and-reactors.

Muir has the size to be a 3-4 defensive lineman, but he's played in a 4-3 defense his entire five-year career. The same goes for Tollefson playing in a 4-3 throughout his career. He's been a defensive end, but his size would seem to indicate he'd have to play outside linebacker if he were to play for the Packers.

While there's potential for these players to be effective contributors to a floundering Packers defense, it's difficult to see how they fit in Green Bay's scheme.

After pondering about these free agent-targets for the Packers, I took a step back and thought about what the Packers are doing. Are they looking for players to fill niche or specialist roles?

Then I remembered hearing about the New England Patriots' hybrid defense and started to do a little cursory investigation. A quick Google search brought me to an article written by SmartFootball.com's Chris Brown at ESPN's Grantland that he wrote on the Patriots' defense prior this year's Super Bowl.

Brown is one of the country's best minds regarding football Xs and Os, and as such, I've asked him to write for the now defunct Maple Street Press Packers Annuals in the past.

In his article at Grantland, Brown introduced the innovative defense being run by the Patriots under head coach Bill Belichick.

"Aside from discussions of its general mediocrity (or worse)," writes Brown, "the hottest topic about the Patriots' defense has been how hard it is to define. Is it a 3-4 defense (the three-defensive linemen, four-linebacker defense that Belichick has run for two decades)? Or is it a '4-3' (the four-defensive linemen, three-linebacker set that New England has favored this year)? The truth is that they play a bit of both."

After reading through the whole article, which I highly suggest doing, I thought the Packers might be setting themselves up to do something similar based upon their personnel decisions and the need to do something to improve upon last year's performance.

In a nutshell here's how Brown describes the Patriots' hybrid defense: "The Patriots run a 3-4 to one side of the field and a 4-3 to the other, all on the same play. The key to all this is (Vince) Wilfork. He lines up over the center and assumes his traditional spot of run-stuffing, blocker consuming, two-gapping war daddy. Belichick fills out the rest of the pieces based on the strengths and weaknesses of his other defenders."

Certainly, there's a danger in trying to emulate what the Patriots are doing. The Packers may have finished No. 32 in the NFL in total defense in 2011 by giving up an average of 411.6 yards per game, and the Patriots finished No. 31 by allowing 411.1.

However, consider that the Patriots advanced to the Super Bowl and have been one of the league's most dominant teams for the past decade or more. There are far worse places to look for inspiration.

"Of course, nothing Belichick does will transform the Patriots' defense into a great one; they don't have the talent," writes Brown. "But coaching is about more than talent. It's about taking the talent that's available and giving it the best possible chance to succeed. And that's something Belichick does incredibly well."

That kind of sounds what the Packers will be trying to do in 2012. There's obvious holes on the defensive line, at outside linebacker and perhaps at safety if Nick Collins retires. Even though the Packers have the Draft to try and improve their defense, they're not going to construct a perfect roster. They'll have to make due with what they have and hope for the best, and maybe a schematic change will help.

Given the similarities between the Patriots and the Packers and the direction the Packers seem to be headed this offseason, I contacted Brown via email to ask him about the Packers defense. He concurs that the Packers are probably making some changes on defense.

"What I think the Packers are likely doing is what a lot of teams have been doing," said Brown, "which is moving to a hybrid 3-4/4-3 type front where your defensive line has a true defensive end (who usually lines up to the strength of the formation or to the field), a nose type defensive tackle, a three-technique defensive tackle, and then a hybrid DE/LB guy."

So what does this mean for the Packers? It means a return to the discussion about where B.J. Raji and Ryan Pickett are best suited. As Brown noted in relation to the Patriots, Wilfork was the key to running the Patriots' hybrid defense. And who is the Packers' version of Wilfork? Is it Pickett who's greatest strength is his ability to two-gap? Or is it Raji, the up-and-comer?

It makes sense that one of them would play the nose in the Packers' hybrid defense and the other play the two-gap five-technique defensive end position.

Meanwhile, a guy like Hargrove would seem ideally suited to play the three-technique defensive tackle position where he has one-gap responsibilities and can penetrate like he does best.

As for the defensive end/linebacker hybrid, maybe that role falls to Clay Matthews, but perhaps the Packers are already looking forward to the NFL Draft and see all the defensive end/outside linebacker hybrids that will be available in the first round.

It's anyone's guess whether guys like South Carolina's Melvin Ingram, Alabama's Courtney Upshaw, USC's Nick Perry and Illinois' Whitney Mercilus are better suited for end or outside linebacker. But in a hybrid defense like this, they can essentially be both.

"This kind of thing is becoming very prevalent in college and more and more common in the NFL," said Brown. "The advantage it (can) give you is that you can have a four-down front for purposes of stopping the run but your defensive end to the weak side is athletic enough to drop into coverage in man or zone blitzes and so on. In fact, he might be less of a defensive end than just a big linebacker."

The odds that the Packers select Ingram, Upshaw, Perry or Mercilus––or trade up to grab one of them––aren't exactly far fetched. Or maybe Tollefson or Mike Neal plays in that spot too.

That would also allow Matthews to play the weak-side outside linebacker in a role that's not much different from what he already does. Playing the weak side might include dropping into coverage more often, but that's one of Matthews' strengths.

Looking at all the pieces of this puzzle, it's not hard to be intrigued by what Mike McCarthy, Capers and the Packers have in store for 2012.

There's no guarantee they're going to run a hybrid-type defense this season. Maybe their draft board doesn't fall the way they expect  it to, or maybe they're just adding new pieces to their defense now and figuring out how those pieces best fit later.

In any case, all the new blood the Packers are bringing in via free agency and will bring in through the draft is exciting. It will be interesting to see how it all works out.