I don't know if this has been brought up, yet, but by my recollection, yesterday's game was the first time Wagner stayed in to play nickel defense. This is amazing progress for the rookie and a huge next step in his career if he remains a 3-down player throughout the season.
Last year, KJ Wright, a good coverage guy in his own right and intelligent player, was held out of nickel situations so as not to overload him in his first year. Wagner, who was similarly held out up until yesterday, took every snap on defense (I'm almost positive), and added the best game to his resume, collecting 1.5 sacks and stuffing the Panthers option offense. Pretty amazing considering it's only his 5th NFL game.
The coaching staff has obviously been looking to add another element to the nickel defense linebacker position, lately. Last week, Malcolm Smith took most, if not all, of the nickel snaps away from Hill and, to my untrained eye, was a part of the problem with our 3rd down failures. He looked out of synch and lost in coverage (which is understandable considering his lack of playing time).
The team looked elsewhere, yesterday, and the search for that missing element may be over, now. Wagner's deceptively fast, lengthy, and strong (which all helps with his blitzing ability I never knew he had), and maybe most importantly, he's young. What must still be considered our defenses "weakness", our nickel defense has so much room to grow and improve when considering the youth and, relatively, inexperience of the core guys on that side of the ball. Having Wagner as a 3-down player this early in his career is a huge positive in becoming the complete defense we all want to see.