SAN DIEGO -- Players like Manti Te'o, Melvin Ingram, Donald Butler and Jeremiah Attaochu had been role players in terms of leadership for the San Diego Chargers. But with older veterans like Jarret Johnson and Dwight Freeney no longer on the roster, this foursome will have to take on more of a leadership role on defense. Te'o served as the inside linebacker making the defensive calls for the Chargers during offseason work.

Lock: Denzel Perryman, Butler, Te'o, Ingram, Attaochu.

Looking good: Kavell Conner, Tourek Williams, Kyle Emanuel.

On the bubble: Cordarro Law, Curtis Grant, Colton Underwood, Brock Hekking, Nick Dzubnar, Chi Chi Ariguzo, Ryan Mueller.

The good: The average age of this position group is a little over 22 years old, with Conner the greybeard at 28 years old. General manager Tom Telesco has done a nice job of getting younger and more athletic at linebacker. The Chargers are relying on Butler, Ingram, Attaochu and Te'o to make more plays within defensive coordinator John Pagano's 3-4 scheme. Along with that, guys like Williams, Emanuel and Law could be counted on as rotational players in the defense.

The bad: San Diego's projected starting four linebackers of Ingram and Attaochu on the outside, along with Te'o and Butler on the inside, missed a combined 20 games in 2014, so they have to stay out of the training room as a group in 2015. The Chargers also allowed 13 runs of 20-plus yards in 2014, tied for No. 24 in the NFL. San Diego has to do a better job stopping the run and tackling in the open field. "We all can do a better job, especially up front," Teo said. "Just being more stout, knowing where everybody's going to be and just having that mindset that we're going to make a play. Definitely each one of us can do better at that."

Bottom line: The Chargers have the talent already on the roster to develop into an effective linebackers' unit, but this group has to play to its potential. One person who will be important in assuring that happens is new linebackers coach Mike Nolan. A former defensive coordinator and head coach previously in the league, Nolan commands respect from players with his no-nonsense approach. Nolan emphasizes the little things and playing defense with an offensive mindset. "Coach Nolan brings an old-school feel to not only our position, but to the defense as a whole," Te'o said. “He's all about making plays. He's all about doing whatever it takes to put each piece in a position to make a play. It's definitely a good thing to have him here."