(First time poster)
So Jerod Mayo is the best we have, I don't think that is much of a stretch to say. But who would rank second? With all due respect to the veterans on the squad and Brandon Spikes, I believe the answer is Jermaine Cunningham.
Cunningham's stat sheet hasn't been exploding this season, but watching the games it's hard to miss his presence. He seems to get around/set the edge the most consistently of any outside linebacker on the team, gets pressure on the quarterback and has excellent instincts. He is arguably better at every facet of his position than any of his teammates; his meteoric rise up the depth chart after missing the preseason due to injury speaks to this.
What is frustrating, though, is that his pressure doesn't accomplish much because the defense cannot maintain containment of the play, whether that be a quarterback in the pocket or the running back. Having re-watched the long TD run by Hillis from Sunday it was obvious the Cunningham and the other players on the defensive right side contained the play to their side and even penetrated the backfield. However, Rob Ninkovich failed to contain on the defensive left and Hillis went outside, Mayo and Spikes trailing behind him, all the way to the end zone.
Our young, no-name defense isn't meant to make stars of our players; they (and we) shouldn't expect eye-popping stats. What it requires, though, are players who can fill the role their position requires. Brandon Spikes is receiving praise league-wide as a player who can make running backs think twice about hitting an inside gap; Gary Guyton and, more recently, Dane Fletcher have shown the ability to come on in sub-packages and spy a player out of the backfield; Banta-Cain is pretty well suited to duty in obvious passing situations; and Ninkovich has shown some ability to pass rush as well as drop into coverage (his night against the Dolphins was ridiculous). What we lack, unfortunately, are defensive linemen who can collapse the pocket and another outside linebacker to set the edge opposite Cunningham.
Maybe Mel Kiper knows which 23 players the Pats will end up drafting next spring to solve our various problems. I certainly do not. But Cunningham was an under-the-radar pick this season who has already improved our team.
He's no rookie MVP, but for a linebacking corps which has been in need of some help for the past season or two he's been more than solid. Spikes got his starting job first, but Cunningham has grown into something close to an every-down role, switching from OLB in the base defense to DE in passing situations. He is one of a number of young players who have made an immediate impact and will only grow more effective as our defense improves around them.