Dwight Freeney, 13th season
Torn quad in Week 4 cut his season short in San Diego. 2014 return will be highly anticipated as Freeney looks for his first sack in the regular season as a Charger.
Donald Butler, 5th season
Awarded with a big new contract in the offseason, but health has been a concern the past two seasons. Butler has missed seven games since 2012, but he continues to have an impact in every facet on defense (sacks, interceptions, tackles and pass deflections).
Jarret Johnson, 12th season
Career-low 11 games played in 2013, a rare occurrence for the usually durable veteran. Primarily known as a run-stopper, Johnson displayed some pass-rushing ability with three sacks.
Manti Te'o, 2nd season
Missed three games with a foot injury but progressed down the stretch. Te'o registered 61 tackles, including a seven-tackle outing in San Diego's thrilling win over Kansas City in Week 17.
Melvin Ingram, 3rd season
Promising rookie season set him up for success in year two but that was delayed by a torn ACL in OTAs. Ingram returned from the injury to play in four games during the regular season along with the postseason.
Jeremiah Attaochu, Rookie
Was one of the ACC's most disruptive pass-rushers during his time at Georgia Tech. Attaochu was so important that the team elected to trade away a fourth-round draft pick just to move up for his services.
Kavell Conner, 5th season
Once a featured starter of the Colts defense before he was replaced in 2013. Conner plays the run well and can step in at a moment's notice for either Butler or Te'o.
Reggie Walker, 6th season
Inserted into a starting role after injuries to Freeney and Ingram early in 2013. Walker had career highs in tackles (36) and sacks (three) in his first season with the Chargers.
Thomas Keiser, 4th season
Played just 12 games in two seasons with the Panthers, but he earned that total in just one with the Chargers. Keiser surprised with 4.5 sacks and came up with the game-sealing interception in San Diego's epic win over the Broncos on Thursday Night Football.