Really good question...and surprisingly hard to look past the starters and focus on depth!
For instance, just about everybody so far has listed OLB as a depth weakness. But are Banta-Cain & Moore really so bad as backups? If Cunningham & Ninkovich emerge as strong starters, a couple of reasonable vets behind them is respectable. Or is the problem that you'd expect to line up 3 so-called OLBs in a lot of sets -- in which case you could argue that starting 4-3 DE is the problem area?
This is the NUMBER 1 problem spot on this roster, no doubt about it.
When did Ninkovitch change from a stop gap starter who was starting because TBC can't play the run into the next coming of Andre Tippett? I must have missed something. I know he had that game with two ints, but he only had 4 sacks all year and he can't cover a lick, those two ints aside.
TBC is a JAG and might not even make the team. He doesn't play the run well, doesn't cover all that well, and doesn't get a lot of sacks against anybody other than Buffalo. He does do something that nobody else on the team does though, he gets pressure on the QB sometimes, if it isn't too good a team, or too big a game.
Nink is a nice backup and a fair emergency starter, but given the choice I would start Guyton instead of him. I know he is smallish for Belichick's scheme, but he is fast and he is a much better player.
And that leaves NT as my biggest depth worry spot on defense.
The Pats have depth along the D-line at every position, Mike Wright has been a very good NT back-up, Brandon Dedrick showed some flashes last year, Ron Brace has been kind of disappointing so far, but he isn't that bad as a third or fourth NT option. The Pats are in pretty good shape on the nose.
WR runs shallow, but the abundance of TEs keeps me from feeling too worried. Though if Taylor Price doesn't make the opening day 45, I'll start worrying more.
WR is the area of the team that could use a little sprucing up. The Pats have nobody who can stretch the field for Brady. They tried Tate as that guy, but he couldn't get open, and when he did get pen he dropped the ball. Welker is a second/slot guy. Edleman is Welker's backup. Price showed some flash in preseason and at the end of the season, but playing well when the game doesn't matter is much different than playing well all of the time. Dione Branch is the number 1 guy right now. He and Brady have a chemistry that is amazing, but he can't stretch the field either. Put Sydney Rice on this team and all of a sudden the recievers can't be double teamed and Brady can choose where to throw the ball.
RB looks OK barring early injuries, with plenty of young legs and versatile skillsets. OT, even without Light, has a reasonable top 4 including a pro-bowl caliber vet and a 1st-round rookie. But the interior OL...
Can it be that nobody else in this thread has mentioned the interior line? To me, C & OG leap out as the top depth concerns on the team.
As long as Mankins comes back the OL should be OK. The short free agency period really hurts a guy like Matt Light. He will probably want more money than a lot of teams will be willing to pay, and he is getting to the point in his career that guard is a better position for him than tackle. He should be signed to two years with an option. If Light doesn't come back then the Pats will need another OL, but there are plenty of decent guys out there.