The Pats need to improve 4 of their front seven on defense in the offseason (assuming they resign Wilfork and if not then 5). Right now, the only starters they have are Mayo (I will assume he will rebound next year after he completely heals), Warren, and Wlifork. I don't care how they replenish the two OLBs, ILB, and DE positions, but they need to figure out a way. It is the lack of a pass rush of any sort that is killing this defense.
I think the offense can correct itself if it isn't asked to win games for the team on a regular basis. They could do that with an excellent OC like McDaniels, but O'Brien has a lot of growing to go to get to that level.
I don't care how the Pats acheive this goal, but they need to do it whether it is through free agency or the draft.