Don't expect to see "3-4" bookend outside linebackers such as Robert Mathis, Tamba Hali and Justin Houston on this list. They will be ranked at a later date in the "edge rushers" category along with "4-3" defensive ends.
The new model for the middle linebacker, Kuechly followed up his Defensive Rookie of the Year award by taking home 2013 NFL Defensive Player of the Year honors. He and Thomas Davis outplayed the more ballyhooed Willis-Bowman duo in a Week 10 win and clinched the NFC South with a dominant performance in Week 16 versus the Saints. Kuechly is the leader and catalyst for the league's best front seven.
When healthy, Von Miller is the NFL's most disruptive linebacker. The question is how effective he will be in the first half of the 2014 season after tearing his ACL in December. Every football player doesn't share Adrian Peterson's alien DNA.
David is one of the most underrated stars in the NFL. His 20 tackles for loss in 2012 were the second most on record for a rookie since the NFL began tracking the statistic in 2000. He was even better as a sophomore, stuffing the stat sheet with 145 tackles, 7.0 sacks, 10 passes defensed and five interceptions. Ignored in the Pro Bowl voting, David actually merited Defensive Player of the Year consideration.
Davis is not only the league's preeminent coverage linebacker -- he also shares high-end closing speed with Timmons. Teaming Timmons with first-round rookie Ryan Shazier should give the Steelers one of the league's most dynamic tandems. ... Johnson earned his first Pro Bowl berth in 2011 after setting a franchise record with 179 tackles. He's been playing at the same high level ever since.
Wagner was one of six players to average over 10 tackles per game in the second half of the 2013 season. ... Mayo is one of the five most important players on the Patriots' roster. He and Jamie Collins will be a versatile three-down tag team, capable of hanging with tight ends and scat backs. ... Burfict led the NFL in tackles, taking over as the backbone of the Bengals' defense when Geno Atkins when down with an ACL injury. ... Levy is coming off a breakout season, leading all linebackers with six interceptions while pitching in 15 pass breakups.
Cushing is a difference-maker in the Texans' defense but has to prove he can stay healthy after missing 20 games over the past two seasons with a pair of major injuries. ... Cardinals fans were campaigning for Dansby as Defensive Player of the Year after he led the team in tackles, passes defensed and interceptions while pitching in 6.5 sacks. ... Briggs is on the brink of his decline phase entering his age-34 season. ... Trevathan emerged as one of the Broncos' most valuable defensive stars during the Super Bowl run. ... Wright has the potential to rival Thomas Davis' coverage skills.
Solid starters: Daryl Smith, Stephen Tulloch, James Laurinaitis, Paul Posluszny, Jerrell Freeman, Donald Butler, Dont'a Hightower, Akeem Ayers, DeMeco Ryans, David Harris, Chad Greenway, D'Qwell Jackson, Koa Misi, Brandon Spikes
Smith was an upgrade on the late-era Ray Lewis in Baltimore. ... Tulloch is coming off a career year, finishing second among inside linebackers in stops (tackles resulting in an offensive failure), per Pro Football Focus. ... Credit Colts general manager Ryan Grigson for pilfering Freeman from the CFL. ... Ayers has to prove he can make the transition to Ray Horton's scheme, where he will be charged with harassing quarterbacks after notching only one sack in 2013. ... There was talk in Philadelphia that Ryans might have to take a pay cut after playing 96 percent of the snaps last season. That rarely bodes well.
Greenway's play fell off last season after a pair of Pro Bowl appearances in 2011 and 2012. ... Jackson is steadily declining, but he should still help a Colts defense that was trashed by LeGarrette Blount in the playoffs. ... Misi should be an upgrade on Dannell Ellerbe as Kevin Coyle's middle linebacker. ... Spikes is excellent in run support but rarely plays on passing downs.
Potential vs. production: Alec Ogletree, Mychal Kendricks, Bruce Irvin, Jamie Collins, Sio Moore, DeMario Davis, Emmanuel Lamur, Bruce Carter, Zach Brown, Jon Bostic, Manti Te'o, Paul Worrilow, Joplo Bartu
Ogletree can be a big-play machine but was too often out of position as a rookie. ... Although Kendricks offers All-Pro upside, Pro Football Focus credited him with more missed tackles than any linebacker. ... Irvin profiles as a double-digit sack artist; can he pull off a breakout season after undergoing offseason hip surgery? ... Collins is a good bet to "make the leap" in his second season. ... The Raiders finally have the making of a defensive nucleus in Moore and rookie Khalil Mack.
The Bengals reportedly view the hyper-athletic Lamur as a Kam Chancellor type of player with safety skills at linebacker. He's capable of filling the box and erasing tight ends in coverage. ... Carter had a disastrous 2013 season after showing plenty of promise in 2012. ... To a lesser degree, the same could be said of Brown. ... The Bears went through a stretch of historically inept run defense following Bostic's insertion at middle linebacker last October. ... Worrilow and Bartu exceeded expectations as undrafted rookies in Atlanta last season.
Declining? Dannell Ellerbe, Kevin Burnett, A.J. Hawk, Wesley Woodyard, Curtis Lofton, Brad Jones, Nick Roach, Erin Henderson, Perry Riley, Rey Maualuga, David Hawthorne, Jon Beason, Spencer Paysinger, Russell Allen, Philip Wheeler, Keith Rivers, Mason Foster, Geno Hayes, Craig Robertson
Ellerbe and Wheeler were free-agent busts in Miami. ... Burnett is now strong against the run but exposed in coverage -- the opposite of his early-career skill set. ... Hawk wasn't stiff enough against the run last season. ... Woodyard was yanked from the Broncos' starting lineup last season after a Pro Bowl-caliber 2012 campaign. He can still help the Titans in coverage. ... Jones could lose snaps to Jamari Lattimore, who flashed as an injury fill-in. ... Beason helped turned the Giants' defense around at midseason but is doubtful for Week 1 after suffering an offseason foot injury.