Let's clarify one thing immediately: The New England Patriots defense is indisputably worse without Vince Wilfork. Apart from Tom Brady, Wilfork may very well be the most indispensable player on the roster, and his season-ending Achilles injury leaves a massive hole (literally and figuratively) in the middle of the defense.
The Patriots have no way of directly replacing their All-Pro defensive tackle. In the week before Super Bowl XLVI, Grantland's Chris Brown wrote an excellent piece on how Wilfork's dominance allows the Patriots to play a malleable scheme that includes both 4-3 and 3-4 concepts, based on individual strengths. That versatility is now gone.
However, the Patriots do possess the personnel to adapt and change their defense. And while drop-offs in production will invariably accompany these adjustments to new schemes, a closer examination reveals these shortcomings should not be fatal.
No one is arguing the monumental importance of Wilfork, or that the Patriots' Super Bowl aspirations took a disturbing hit. However, let's break down how New England might adjust without its defensive rock, and show why Wilfork's loss is closer to a staggering body blow than an unconquerable knockout punch.
Against the Run
This is where the Patriots will miss Wilfork the most, and the section that requires the bulk of analysis. Indeed, Wilfork's impact is so great that New England may have to adjust its scheme rather than attempting a simple personnel exchange.
However, it is worth mentioning that the Patriots actually have a highly capable defensive tackle behind Wilfork. Tommy Kelly is no stranger to anchoring lines, and the 32-year-old has looked rejuvenated after years on miserable Oakland teams. This graph from advancedNFLstats.com, which plots Win Probability Added (WPA) vs. Expected Points Added (EPA), illustrates Kelly's productivity this season:
And yet, Kelly is not the same type of tackle as Wilfork, who controls two-gaps at will. Kelly has graded out at minus-1.1 on run defense (subscription required) for the year, and certainly makes a greater impact as a one-gap upfield rusher. So what can the Patriots do to provide the middle of the line more support against the run?
The answer likely lies in the next level of the defense, namely thumping linebacker Brandon Spikes. With the Pats playing heavy doses of nickel defense, Spikes has seen a big reduction in snaps, playing only 40 percent of the snaps after playing roughly 72 percent last season.
However, the Patriots may have already shown a wrinkle that will allow Spikes to play without compromising the defense's pass-first philosophy. As NESN's Doug Kyed illuminates, the Pats played large stretches of the game against Tampa Bay in their base 4-3 defense, but with an extra corner subbed in for Steve Gregory:
Bill Belichick pulled a safety in the base defense, choosing instead to keep three cornerbacks and three linebackers on the field. It came out looking like a hybrid base/nickel defense.
New England showed the look multiple times with four down linemen, Jerod Mayo, Brandon Spikes and Dont’a Hightower at linebacker, Aqib Talib, Alfonzo Dennard and Kyle Arrington at cornerback and Devin McCourty as the lone safety.
The look was likely utilized to keep Spikes in the defense to help out in the run game, since Doug Martin is so dangerous. But it also showed that Belichick is confident enough in Talib, Dennard and Arrington’s pass-defense skills that they only need one safety to help out over the top.
Not coincidentally, Spikes played his most snaps of the season and had his best game, grading out at plus-2.9 overall (subscription required), including a team-high plus-2.3 against the run. While the fourth-year linebacker has not progressed as well as hoped in pass coverage, he still brings an overpowering authority and attitude against the run.
Here's an example of Spikes' physicality. On this run, the fullback attempts a down block on Spikes. If it works, notice how much room Doug Martin would have to run up the middle:
However, Spikes shoves aside the Tampa fullback, plugging the hole and stuffing Martin for a harmless two-yard gain:
After Wilfork went down on Sunday, the Pats did not necessarily turn to this package, but had Spikes come in to inject some downhill run stuffing. Here he nimbly avoids traffic in the middle and stops Falcons back Jason Snelling:
Spikes is not a perfect linebacker by any means, and potential overexposure could compromise the Patriots pass defense that has made such encouraging strides in 2013. However, more than any other player, he is best equipped to try and offset Wilfork's enormous impact against the run.
Against the Pass
While Wilfork has built his reputation upon immaculate run-stuffing, his impact in the passing game has always been underrated. His ability to draw consistent double-teams has opened up one-on-ones for edge-rushers like Rob Ninkovich and Chandler Jones, even if Wilfork rarely gets home to the quarterback. The 2011 AFC Championship Game epitomized this value, as Wilfork's mind-boggling plus-7.0 rating essentially carried the Patriots to victory that day.
However, the Patriots won't suffer as large a drop-off in this facet, especially considering the three-defensive end wrinkles they've introduced at times. On passing downs, Jones will often kick inside and play the 3-technique, where his length and quickness can give less agile guards fits. Here, he outclasses lumbering guard Vladimir Ducasse and sacks Geno Smith for a big loss:
Alternatively, the Patriots may consider using undrafted rookie Joe Vellano, a more natural defensive tackle. At 285 pounds, Vellano is more Little Joe than Big Vince, but his size actually makes him a capable pass-rusher. Against the Falcons, he picked up a 13-yard sack after leaving Atlanta center Peter Konz in the dust with a nifty swim move:
Vellano's presence in the run game is a huge concern, and it might behoove the Pats to try and add more size in the middle. But at least against the pass, Vellano should be a credible option.
When measuring Wilfork's loss, context is important. Consider the offensive rushing rankings of these AFC contenders, both by traditional and advanced metrics:
Those are some mediocre to ugly numbers, as only the Colts jump out as particularly threatening. The Patriots will likely regress from a borderline elite run defense to a slightly above-average outfit. That is a significant drop to be sure, but certainly not a death sentence.
So long as the Patriots do not compromise their improved pass defense, the improved unit should continue holding its own. Combined with the redefined and gradually improving ball-control offense, New England is far from a hopeless squad.
What Wilfork's injury truly eliminates is any margin of error in terms of injury luck, particularly on defense. If Aqib Talib or Devin McCourty were to suffer a similar long-term injury (knock on wood), the Patriots might be staring at a deficit too difficult to overcome. But for now, Pats fans should not give up on their team's Super Bowl aspirations.