Players with four or more seasons have their base salaries guaranteed if they're on a roster Week 1, so cutting those guys isn't saving any money.
http://profootballtalk.nbcsports.com/2010/08/31/refresher-on-the-vested-veteran-guarantee/
I don't know why I even bother to point that out, as no one thinks this can or will happen.
Thinking more on the Ryan-for-Gilmore swap, Ryan's role was always pretty underrated. He was a guy with meh physical tools, but he knew every position in the defense - outside CB, slot, he even got the odd rep at safety. He really helped stabilize the D last year, taking on a role where he played slot in nickel or outside in base, which is pretty tough sledding. Moreover, he came from the same Rutgers system as McCourty and Harmon, and he and Harmon were teammates for three years in college, and they played together professionally for years, so those guys were on the same page.
Not only have they replaced Ryan with Gilmore - who does not appear to know the defense or communicate well with the other DBs - from a roster perspective, it seems they've tried to slide Rowe into Ryan's slot duties and it hasn't paid off. On paper, it makes sense - Rowe is a big, agile guy who played some safety in college - but the slot is one of the most complex positions in NE's D (you basically have to know all the CB and all the LB assignments) and he doesn't seem to be getting it either. His tackling was a problem yesterday, too, which is a no-no inside. So now you have two guys who don't really know what they're doing and aren't on the same page, and McCourty is trying to do way too much to compensate and he's screwing up, too, and now no one trusts anyone and no one can just do their job.
Rowe's injury might be a blessing because he seems to be one of the problems. Fixing the slot CB issue will help both the pass and run D - maybe they put Jonathan Jones in there, or maybe Butler bumps inside in nickel, or maybe it's McCourty or Chung in the slot with the other S (Harmon and
Richards I guess) taking on bigger roles. Or maybe they need a PS guy to step up. If they can nail down the slot, then Gilmore a) has a simplified role (outside CB) and b) is the only question mark in terms of communication, and then they can focus on fixing that. That's probably a more realistic recipe than benching the big money man.