Last season the New England Patriots had one of the best offseasons of any team when they acquired cornerbacks Darrelle Revis and Brandon Browner. One could make the case that last year's team was the best Patriots defensive unit in 10 years.

Things didn't look good when both Revis and Browner were not re-signed this offseason. To escalate concerns, defensive captain Vince Wilfork left for the Houston Texans. Without Revis, Browner and Wilfork, a lot of doubt crept in for the Super Bowl champions.

Despite all this, the Patriots defense is actually right on par with last year's squad statistically. Last year Bill Belichick's squad ranked eighth in yards allowed and 13th in points against. This year they ranked eighth in yards allowed and 13th in points against, almost the exact same as last year. Only once this season have the Patriots allowed more than 30 points, which came in Week 2 against the Buffalo Bills. In all fairness, a lot of those pints were given up in garbage time at the end of the fourth quarter.

So how is this? How is the Patriots defense playing just as competitive as last year even though they lost their two big name corners and best defensive tackle?

The biggest reason is quarterback pressure. The Patriots secondary isn't as good as last year so Matt Patricia and Belichick are frustrating quarterbacks at the line of scrimmage rather than in the secondary. Last season the Patriots defense tallied 40 total sacks, 2.5 per game. That ranked 13th overall in the NFL last season. This year the Patriots defense has racked up 26 sacks in just seven games, 3.7 per game. That ranks second overall in the NFL this season behind only the Denver Broncos.

You could easily make the case that Jamie Collins is the Defensive Player of the Year for the first half of the season.

And that brings us to the linebacker position. The Patriots are absolutely loaded when it comes to the middle of their defense. Dont'a Hightower and Collins create a great attack with ends Rob Ninkovich and Chandler Jones coming off the outside. Collins is starting to remind fans of the great Tedy Bruschi because he is so versatile.

"Jamie, it seemed like had 20 tackles. I don't know what he had out there, but he was in on a lot of them. Had a couple good pressures, and Jabaal Sheard gave us some pressure as well. So, we had a good mix of run defense, pass rush, and we had a lot of different guys who stepped up and made plays. But Jamie seemed to be all over the field," Belichick said.

Super Bowl hero Malcolm Butler has certainly had his moments this year, but we know he's not Revis. Belichick will continue to use Butler on man-to-man against the opposing team's best wide receiver. Considering this is his first full season as a starter, he's done a very good job. Jamaican-born safety Patrick Chung and Devin McCourty have created a reliable pass defense. It's pretty safe to say Chung fits in better with the Patriots than he did with the Philadelphia Eagles.

The Patriots defense will have to remain strong if they want to compete with the undefeated Broncos and Bengals in the AFC for the No. 1 seed.

Follow Damon Salvadore on Twitter @DamonSalvadore1