I sure hope the NFL doesn't change the preseason format. The four-week schedule seems like just the right amount of time to give teams a chance to evaluate talent in real time. And young players, as well as, new players to the team, get their chances to make their best, first impression.

The New England Patriots are known to have a steep learning curve, and Coach Belichick is as demanding as any in the league. Some new defensive players, like Darrelle Revis, are virtually guaranteed a roster spot. And no one is scrutinizing Vince Wilfork to see if he has what it takes to survive cuts next week.

There is reason to be optimistic of the defense as a whole. We all know that the secondary got better just by adding Revis to the mix. He makes everybody better by his presence. And lining up next to big Vince has to be inspiring to the greenest lineman.

In fact, barring injuries and looking just at the first-team defense, opposing offenses should be concerned that this D will not be easy pickings like the 2013 version. We will assume for now that there will not be the severe devastation of the D roster through injury. But be that as it may, depth has been a big concern this off-season, and fans know that even the best players need a "relief pitcher" every so often.

With that in mind, the only group of starters that has even minor concerns, would be, in my mind, the secondary, and more specifically, the safeties. Devin McCourty appears to be the only sure thing back there, and the situation has been made clear by the revolving door during camp and the first two preseason games.

The one player that looks like the difference-maker is Malcolm Butler. Let's forget the knock on him that he isn't strong in coverage. He is out there making plays on the ball and that is effective safety play. Don't overlook the hitting of Patrick Chung either, which was on display against the Eagles this past week.

Nate Ebner is also showing a nose for the ball, giving the Pats hope that all is not hopeless in center field. Along with Travis Hawkins and Duron Harmon, Belichick will have little problem filling-out the back-end by the start of the regular season.

The linebacking corps is equally thin, but the apparent emergence of James Anderson is not totally unexpected, and his skill set makes him instantly valuable in both the running and passing games. While few others seem ready to contribute behind the big-three, don't ignore defensive ends as rotational help in that department. We all know how versatile guys like Rob Ninkovich can be.

Up front, the renewed emphasis on the four-man front has brought new life to the team. Dominique Easley is starting to get involved, and his impact should be huge and immediate. Sealver Siliga and Joe Vellano made good contributions last year, and should be there to step up their play in 2014. Marcus Forston, Jerel Worthy, Ben Bass, Zach Moore, and a few others are all getting opportunities to add value to the depth chart, as well.

The Patriots may actually find themselves in the enviable position of flashing the ability to mix-up their looks on defense to confound offenses across the league.

Players who have maximized their opportunities so far:

Malcolm Butler

Nate Ebner

James Anderson

Patrick Chung (hold that hate mail)

Travis Hawkins and Steve Beauharnais... making tackles

Jerel Worthy and Joe Vellano

and no doubt Dominique Easley will soon, too.

Time may be running out on some bubble players, and week three will certainly be do or die for many of them. The above mentioned players have the best shot at making the final roster and solidifying what  is shaping up to be a much better defensive unit than what hobbled through last season.