Rob Gronkowski’s back injury is worse than originally reported and the tight end will have surgery on Friday. The expected recovery time is around eight weeks.

Even in his limited time on the field this season, Gronk has been his usual dominant self. Among tight ends with at least 10 targets, Gronkowski is first in Reception Net Expected Points (NEP) per target (1.32). It’s clear he’s a massive matchup problem for opposing defenses and he’s one of, if not the, most important pieces of the New England Patriots' offense.

Tom Brady has also historically been much worse statistically without Gronkowski in the lineup. Here's Brady's per game splits playing with and without his top tight end (Numbers courtesy the RotoViz Splits App).

While the loss of Gronkowski could derail the remainder of this season, the Patriots might be better positioned than ever to cover the loss. This news hurts them, but New England is probably going to be fine.

Black Unicorn

Obviously, the biggest part of replacing Gronkowski is the presence of Martellus Bennett. Bennett was acquired from the Chicago Bears, along with a sixth-round pick, in the offseason for a fourth-round pick. At the time, this trade seemed like a great move for the Patriots, who could destroy defenses in two tight end sets. This had been the case when Gronkowski and Bennett were on the field together, but Bennett has carried his own stand alone value, too.

Overall, Bennett is ninth among tight ends in Reception NEP per target (0.79). While he does get a boost from having Gronkowski on the field at the same time, he's seen a fair amount of time as the top tight end option. Gronkowski missed the first two games of this season with a hamstring injury and played sparingly the following two weeks. He also missed Week 11’s game against the San Francisco 49ers after initially suffering his current injury against the Seattle Seahawks in Week 10.

Here’s how Bennett fared in the games without Gronkowski:

This isn’t the greatest sample of games to show what the offense could be with Bennett as the lead tight end. The first four games were played without Brady at quarterback and the Week 11 game was against a 49ers defense that didn’t need much manipulation to control -- Brady even looked like he was on cruise control.

But, when Bennett was installed as a key piece of the game plan, he was dominant. And even when he wasn’t, the offense got by just fine.

Other Weapons

One of the things that makes the Patriots great is how many different ways they can beat opponents. The idea for this season was to create mismatches with two tight end sets, but that’s not the only way New England was going to move the ball.

Even when combining Gronkowski’s and Bennett’s targets (92), Julian Edelman leads the team at 99. Edelman hasn’t been nearly as efficient as in years past -- he’s just 69th in Reception NEP per target among 72 receivers with 50 or more targets -- but he remains a big part of the game plan each week. He’s gotten less than five targets just once and with Gronkowski out in that game against the 49ers, Brady threw to Edelman 17 times.

Chris Hogan, Malcolm Mitchell, and Danny Amendola are all competent enough to take over increased playing time if needed. Hogan has been the one to play the most snaps (69.5 percent), but Mitchell’s performance has been coming on lately, with two touchdowns in Week 12 against the New York Jets. New England was also no stranger to running 11 personnel. They had three receivers on the field 42 percent of the time last season per the Football Outsiders Almanac, just behind the time with two tight ends on the field (43 percent).

The return of Dion Lewis also comes at a great time. While he’s been limited the past two weeks with just 12 targets, 7 receptions, and 11 rushing attempts, he’s likely to see a bigger role as the season continues. James White has been the second-most targeted Patriot in the passing game and it wouldn’t be a surprise to see Lewis continue to re-take that receiving back role.

In just seven games last season, Lewis had 36 receptions on 50 targets for 388 yards while also rushing 49 times for 234 yards. He was one of 20 running backs to be targeted 50 or more times last season and his 0.51 Reception NEP per target was fourth-most among those backs.

New England also has a strong running game to rely on. As a whole, the Patriots rank 11th in Adjusted Rushing NEP per play. LeGarrette Blount has the fourth-most carries in the league and ranks 14th among 29 running backs with at least 100 carries in Rushing NEP per attempt.

Future Outlook

By our nERD metric, the Patriots are the best team in the AFC and they’re second in Super Bowl odds behind the Dallas Cowboys. We should still consider the Patriots the AFC favorite without Gronkowski. The closest AFC team to New England in our rankings is the Denver Broncos and they’re currently fighting just to make it in as a Wild Card.

An eight-week recovery timetable for Gronk’s injury would possibly allow him to return sometime during the first week of February. The Super Bowl is going to be played on February 5. This also assumes the Patriots don’t put Gronk on injured reserve and play with a 52-man roster for the remainder of the season. Quarterback Jacoby Brissett returned to practice this week off injured reserve, which takes away the Patriots’ return designation.

While the Patriots might be ok, there should be some real concern about Gronkowski. He’s undergoing a surgery similar to that of J.J. Watt, and while Watt returned to the field seven weeks later, he looked nowhere near his dominant self and was sent back to injured reserve after just three weeks this season.