PHOENIX – Chad Brown had admired Bobby Wagner's game from afar.

Then, Brown got an up-close-and-personal look at the All-Pro middle linebacker as the sideline reporter for Westwood One's coverage of the Seahawks' game against the Arizona Cardinals at University of Phoenix Stadium on Dec. 21.

"I think Bobby Wagner is the most-underrated player on the Seahawks," Brown said Tuesday during the break between the New England Patriots' and Seahawks' sessions at Media Day. "I know he gets some pub, but I think he's really the key to the defense."

And Brown should know, because no one in franchise history has played the outside linebacker position better than Brown did from 1997-2004. He was a two-time Pro Bowl selection (1998 and 1999); was voted second-team All-Pro in 1998; led the team in tackles for three consecutive seasons (1997-99), including 150 in 1998; and is fourth on the franchise's all-time list with 744 tackles and fifth with 48 sacks.

Suffice it to say that Brown knows more than just a little bit about how to play the position, and how the position should be played. And he is impressed with the way Wagner plays the middle.

Remember, it was Wagner's return from missing five games at midseason with a toe injury that coincided with the eight-game winning streak the Seahawks carry into Sunday's matchup with the Patriots in Super Bowl XLIX at University of Phoenix Stadium. The Seahawks have allowed an average of 9.8 points during that run, while Wagner has averaged 9.1 tackles.

"Obviously when he came back from the toe injury, the defense took a huge step forward," Brown said. "But there's a reason why. His ability to cover people allows the Seahawks to keep base defense on the field even when opponents go with three receivers, which is amazing. I really saw that when I was on the sideline for the Seahawks' game against the Cardinals.

"Bobby Wagner's ability to cover deep when they go Cover 2 has a huge domino effect. Now, (strong safety) Kam Chancellor can play more aggressive. Now, (free safety) Earl Thomas is not so worried about the middle of the field because Bobby Wagner's back there. So now Earl can give the corners more help and the corners now have more confidence because they know Earl Thomas has their back."

So Wagner's return to a defense that has led the league in average points allowed the past three seasons and in average yards allowed the past two seasons can't be overstated. And it will be a key factor on Sunday, as well, because of the way the Patriots work the middle of the field in their passing game with tight end Rob Gronkowski and slot receivers Julian Edelman and Danny Amendola.

"It's amazing how Bobby Wagner's return and his ability to play that middle so well is really the lynchpin to the entire Seahawks defense," Brown said.