The New England Patriots have had a relatively quiet off-season so far in free agency with only a few additions and losses. Their biggest loss so far must be BenJarvus Green-Ellis who left for the Cincinnati Bengals while Brandon Lloyd's addition could be massive for the offense as a whole.

Green-Ellis' replacements were drafted last year while most of the other losses, such as Mark Anderson to the Buffalo Bills, have already been dealt with, to replace Anderson the team added Trevor Scott from Oakland.

What could ultimately prove to be more vital this year, at least prior to the draft, are the respective moves that the Patriots' divisional rivals made. Here is a look at each team and how they stack up to the reigning division champs.

New York Jets:
The Jets' two biggest acquisitions during free agency were the additions of Tim Tebow and LaRon Landry. While re-signing Mark Sanchez and Sione Pouha were more important moves, adding Tebow and Landry were bigger because they represent the difference in the Jets' roster entering next season.

Neither is a guaranteed impact player. Landry has severely struggled to stay on the field during his career and is generally overrated because of his physical talents opposed to his actual play on the field. He can get lost in coverage often but should supply some dominant run support. Landry may have beefed up this off-season to cover Rob Gronkowski but if he isn't healthy to stay on the field, that will be worthless to the team.
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Adding a backup/situational quarterback is never going to make a major impact on a team's Xs and Os but Tebow's impact stretches through the whole roster. With Tebow on the roster, the team now has a legitimate threat to create a quarterback controversy in New York. Considering the Jets' locker-room problems last season, that could be a major issue heading into the year. The Jets gave up draft choices and didn't invest heavily in putting weapons around Sanchez. Instead of helping their quarterback to grow and perform against the Patriots, they brought in Chaz Schilens as a cheap option with more hope than expectation.

Miami Dolphins:
The Dolphins entered this off-season with two clear needs which could have pushed them closer to the Patriots if filled. Those needs were defensive end and quarterback. Neither were filled.

With Jason Taylor retiring and the team hoping to transition to a hybrid defense, the Dolphins are all but certain to draft a defensive end if they don't chase Ryan Tannehill. Despite the plan to change scheme, the Dolphins re-signed Paul Soliai, who is strictly a 3-4 nose tackle, which shouldn't hurt the Patriots at all. Losing Kendall Langford lowers the quality of the front overall at a position which is vital for matching up to the Patriots schematically.

Offensively, the Dolphins took a major step backwards. They never got close to signing Peyton Manning, while their best receiver, Brandon Marshall, who put up big numbers against the Patriots last year, is now in Chicago reunited with Jay Cutler. Without Marshall, and only David Garrard coming in to compete with Matt Moore playing behind an offensive line which hasn't significantly improved, even the Patriots defense should be able to shut down the Miami offense next year.

Buffalo Bills:
The Bills are the team which really took strides this off-season towards catching up to the reigning AFC Champions.

With Matt Light potentially retiring, he or his replacement will now have to deal with Mario Williams twice a year. The Bills signed Williams to a huge deal as they transition to a 4-3 defense this off-season. Their defensive line, a vital cog in disrupting the Patriots' offense, is now arguably the best in the whole league. With Marcell Dareus and Kyle Williams inside, Mario Williams outside and former Patriots' player Mark Anderson bookending him on the opposite side, the Bills will be able to pressure Tom Brady without blitzing.

In particular, changing over to a 4-3 defense will allow Kyle Williams and Marcel Dareus to pressure Brady through the middle. Brady has never handled pressure in his face well and is one of the worst quarterbacks in the league at throwing off of his back-foot. With Logan Mankins tearing an ACL, and Robert Gallery arriving to take his place, the Bills will provide the Patriots offense with a stern test next year. Considering they picked him off four times in Buffalo last year, the team definitely has the secondary to capitalize on added pressure upfront.

The Patriots will still enter the season as the clear favorites in the AFC East, but the division should see some change as the Bills take a step forward and the Jets look set to fall off.