Kamerion Wimbley (OAK)
Among the experienced 3-4 OLBs who are likely to be available, Wimbley probably makes the most sense for the Patriots. He's shown a propensity for getting to the quarterback with 35.5 sacks in his first 5 years in the league. Wimbley is young, has the versatility to play at DE and could be one of the better OLBs available. He is at his best when he is asked to rush the passer, so he could fill an important need for New England. If the price is right, he could easily be a Patriot.
LaMarr Woodley (PIT)
Woodley is just 26 and one of the league's premier pass-rushers as an OLB in the 3-4. The major question would be his availability. The Steelers will almost certainly put the franchise tag on him, but if they fall asleep at the switch or if the new CBA voids the franchise tag (very unlikely), he would make a huge impact for the Pats. It would take a mint to sign him, but his big-game experience and leadership could make him well worth the investment. He'd be even better than Adalius Thomas in his heyday.
Tamba Hali (KC)
Hali is also likely to see the franchise tag, so the most realistic chance for him to be available would be a prolonged holdout to force a trade (unlikely) or the possibility that the new CBA does away with the tag altogether (equally unlikely). Hali led the conference in sacks with 14.5 last season and terrorized opposing quarterbacks all season. He recorded 37 percent of his team's sack total, and his constant pressure was one of the driving forces for a defense that was good enough to win the division and make the playoffs. He could be the every-down linebacker New England's defense needs to take the next step in the playoffs.
Antwan Barnes (SD)
Barnes does not appear to have the physical make-up to be an every-down OLB in the 3-4 at just 6'1" and 250 pounds, but he could contribute as a pass-rusher in sub packages. He got plenty of pressure on Brady in Week 7 with two sacks on a limited number of snaps, and that performance may have opened a few eyes on the Patriots coaching staff. He probably wouldn't require much of an investment since his value as a 3-down player is somewhat limited.
Mike Vrabel (KC)
This name might be familiar to a few Pats fans since he won three Super Bowls with New England before his trade to Kansas City. At age 36 to start the 2011 season, Vrabel will be a dinosaur in NFL terms. He is definitely past his prime as an every-down linebacker, but even at his advanced age, he could be useful in sub packages on a limited number of snaps. His veteran presence could also aid in the development of the inexperienced OLBs on the current roster.