I don't know why Crable is a mystery. He was highly drafted by Belichick. He played very well in preseason. The only question I have is whether he is 100% healed from his injuries. If he is, then I expect him to continue to develop and to compete for a 2010 starting position at OLB.
Bruschi is a question mark. The slide has begun. The only question is how fast and how long he can be a significant contributer.
I expect Banta-Cain to be brought into patriot game shape. I expect that Belichick asked him to make that comittment. At very least, he is the #5 OLB and a fine special teamer. At best, he will be competing for reps with Woods.
With McKenzie injured, there is certainly an opportunity for an UDFA to beat out Alexander, as the emergency #4 ILB and top special teamer. However, barring injury, or a Bruschi retirement, I think this unlikely to happen, but it certainly could. I am satisfied with Banta-Cain and Alexander as emergency linebackers and special teamers. We used to have Izzo and Davis. I suspect Belichick is OK with them also.
In any given game, six linebackers probably get 95% or more of the reps on the defense. We need an additional OLB backup and a couple of special teamers.
OLB: Thomas, Woods, Crable, Redd
ILB: Mayo, Guyton, Bruschi
LB/ST: Banta-Cain, Alexander
Well now, I'm reluctant to classify Adalius as either an ILB or an OLB. The more Pees can move him around in the formation the more difficult it will be for offensive coordinators to game plan around him. Mayo is fixed inside, but flexibility with Adalius could really help the defense for NE.
I expect Guyton and Woods to play well, and I expect to see improvement from Redd - I just don't know how big a jump he'll make. BB has been comfortable with Alexander as a #4 ILB, he'll be good in that role as a primary Special Teams player.
Bruschi, Crable, Banta-Cain, and Craig are open questions for me, TBC because he was playing at a heavier weight in SF so his conditioning is going to be a concern, the two youngsters for being unknowns though I've seen good things from both in preseason or college. Bru is still an asset in situational play and as a mentor to the kids, I expect Guyton to allow Bru to be used more sparingly. Ciurciu and Appleby, who can say.