ENGLEWOOD, Colo. -- Not once in the regular season or playoffs did the Broncos' linebacking corps look as it was intended.

Stewart Bradley, who had worked his way onto the first team at middle linebacker, was lost for the season to a wrist injury in a preseason loss at Seattle. Strongside linebacker Von Miller missed six games to a suspension and four more (including the playoffs) to a torn anterior cruciate ligament. Wesley Woodyard, initially projected to be the weakside linebacker, ended up moving to the middle, but he missed two games to a neck injury and then was shifted from every-down to sub-package work in December and January.

A return to form for Miller is essential to the calculus of the position, as long as he remains a strongside linebacker on base package downs. But the emergence of 2012 draft pick Danny Trevathan on the weak side helps.

All the questions remain at the middle, with Woodyard, Bradley and late-season starter Paris Lenon all due to hit free agency.

The Broncos have internal options. Nate Irving filled in on the strong side and had arguably the best individual game of his career in Super Bowl XLVIII. Steven Johnson helped stuff the Chiefs in a goal-to-go situation in Week 11 and has flourished on special teams. And Lerentee McCray, an undrafted signee last year, had some flashes of brilliance before he suffered a season-ending injury in the preseason finale; if he had made the 53-man roster, it would have come as no surprise.

But the Broncos' reported interest in former Browns linebacker D'Qwell Jackson shows that they're not interested in standing pat. Four teams are reportedly in contention for Jackson's services, but the signal is clear: the Broncos would like to improve the position, and could use free agency to do it.

UNRESTRICTED FREE AGENTS:

Karlos Dansby, Arizona: He had one of the best seasons of his career in his return to the Cardinals, and remains one of the league's best linebackers in pass coverage. Cardinals head coach Bruce Arians told KMVP in Phoenix that Dansby was offered a contract "the day after the season ended," and the Cardinals clearly want the 32-year-old back -- but at the right price.

Daryl Smith, Baltimore: Defensive Coordinator Jack Del Rio knows Smith as well as any coach could from their seven-plus seasons together in Jacksonville. Smith turns 32 on March 14, but had one of the best seasons of his career last year, and broke Ray Lewis' single-season team record for passes defensed with 19.

Calvin Pace, N.Y. Jets: At 33, the 265-pound Pace revived his career with a 10-sack, 53-tackle season, although much of that came from the increased attention opponents devoted to the Jets' interior pass rushers. He's a more natural fit in a 3-4 defense than a 4-3 alignment, and his age could leave him on the market longer than others, but he hasn't missed a game in three years and proved last year he still has plenty left.

James Anderson, Chicago: His size (229 pounds) has made him an awkward fit at a strong-side linebacker, although the Bears did use him in an every-down role last year. Broncos Head Coach John Fox and Linebackers Coach Richard Smith got Anderson's best season in 2010 when they were all in Carolina; that year, he was an effective pass rusher and was adept in coverage. His struggles in Chicago could be chalked up to issues for the entire defense.

Brandon Spikes, New England: Spikes was brilliant in spurts for the Patriots last year, particularly in the first half of the season. But he was not as effective after Jerod Mayo was lost for the season, and the contentious situation that followed his placement on injured reserve in the playoffs raises questions.

Jon Beason, N.Y. Giants: John Fox saw the best of Beason in Carolina; he was a Pro Bowler and team captain by his second season and appeared to be en route to a brilliant career. Injuries intervened, and the Panthers dealt him to the Giants last season, where he returned to every-down work. Beason isn't as strong in coverage as he was before the injuries, but the Giants liked his play, and according to the Newark Star-Ledger, are attempting to re-sign him.

Wesley Woodyard, Denver: After a breakthrough 2012 season, 2013 was more difficult for Woodyard. He was moved to middle linebacker before the start of the season, suffered a neck injury in a Week 5 win at Dallas and in December lost his grip on every-down work, and was used in sub packages thereafter. Woodyard's leadership in the Broncos' locker room is above reproach, and he has been a season-long captain since 2009. But his future path could be determined by the answer to one question: will a team be willing to use him on every down?

Perry Riley, Washington: Riley racks up tackles -- 244 of them in the last two seasons -- and is durable, having not missed a game in the last three seasons. But he makes a fair amount of plays from behind, and is a better fit as a 3-4 inside linebacker than as a potential 4-3 middle linebacker. Sticking with Washington -- which will maintain its defensive scheme through its head-coaching change -- is likely Riley's best option.

O'Brien Schofield, Seattle: Schofield's injury history is long, highlighted by the torn ACL suffered in Senior Bowl practice in 2010 that depressed his draft stock after a strong career at Wisconsin. Seattle added him in last summer's training camp after the Cardinals waived him, and he contributed a sack in limited defensive work. Schofield had four sacks in the first nine games of 2012 before an ankle injury sidelined him. It's not a question of whether he can be an effective pass rusher; it's a question of whether he can stay on the field. If Schofield's situation doesn't change, there'll always be a lament of "what might have been" that hangs over his career.

Desmond Bishop, Minnesota: He turns 30 in July, but his recent injury issues -- a torn ACL last year and a torn hamstring the previous year -- have limited him to just five games and just one start since 2011. Before his spate of injuries, Bishop was a highly effective all-around linebacker; in the Packers' 2010 world-title season, he was an every-down presence who was effective against the run, in coverage and as an edge rusher. For a team that won't rely on him immediately, he is worth a gamble.

Darryl Sharpton, Houston: A solid two-down linebacker for the Texans, Sharpton was exposed in coverage, but is an above-average run defender who plays with energy.

London Fletcher, Washington: He hasn't filed his retirement papers, although the 16-year veteran indicated in December that he was "99 percent" sure his career was done.

D.J. Williams, Chicago: The former Bronco barely settled in with the Bears before suffering a torn pectoral muscle that ended his season on Oct. 10. His versatility and ability to play every linebacker spot should give him another chance, but his age (32 in July), recent injuries and suspensions in 2012 likely mean a veteran-minimum, incentive-based contract.

Nick Barnett, Redskins: Barnett is well-known name, but is coming off the least productive season of his career. For the first time in his 11 previous seasons, he wasn't a starter, and at 32, didn't contribute much. Nevertheless, he was a fairly effective starter in Buffalo in 2012 -- he graded out at a plus-6.0 on ProFootballFocus.com's metrics that season -- and could have a bit more left in the tank with a change of scenery and scheme.

Jonathan Vilma, Saints: Knee problems finally caught up to Vilma last year, and he played in just one game. At this point, Vilma's experience and leadership are his best qualities, and he probably fits best in a rotational role to limit his snaps and allow him to hold up.

Paris Lenon, Denver: He acquitted himself well in the Broncos' run defense late last season, but it appears as through the Broncos want to get a bit younger and stabilize the middle. Four different players have started in the regular season at middle linebacker the last two years and another, Stewart Bradley, was the first-teamer before being hurt in the preseason.

OTHERS:

Pat Angerer, Indianapolis; Michael Boley, Cincinnati; Stewart Bradley, Denver; Jonathan Casillas, Tampa Bay; Kavell Conner, Indianapolis; Dan Connor, Carolina; Blake Costanzo, Chicago; Jacob Cutrera, Tampa Bay; Zac Diles, Tennessee; Jo-Lonn Dunbar, St. Louis; Dane Fletcher, New England; Rob Francois, Green Bay; Omar Gaither, Atlanta; Parys Haralson, New Orleans; Adam Hayward, Tampa Bay; Will Herring, New Orleans; Ramon Humber, New Orleans; Rob Jackson, Washington; Edgar Jones, Dallas; Akeem Jordan, Kansas City; Bryan Kehl, Washington; Josh Mauga, N.Y. Jets; Joe Mays, Houston; Rocky McIntosh, Detroit; Marvin Mitchell, Minnesota; Arthur Moats, Buffalo; Keith Rivers, N.Y. Giants; Jordan Senn, Carolina; Ernie Sims, Dallas; Austin Spitler, Miami; Stevenson Sylvester, Pittsburgh; Darryl Tapp, Washington; Reggie Walker, San Diego; Dekoda Watson, Tampa Bay; Jamaal Westerman, Pittsburgh; Jason Williams, Carolina; Will Witherspoon, St. Louis; Frank Zombo, Kansas City.

STREET FREE AGENTS:

D'Qwell Jackson, Cleveland: After being released, Jackson went on a series of visits -- reportedly to Tennessee, Miami, Denver and Indianapolis. At 30, Jackson has put the torn pectoral muscles he suffered behind him and played every game the last three seasons, racking up 417 tackles in the process. It would be interesting to see what Jackson could do as a middle linebacker and two defensive tackles in front of him instead of just one.

Erin Henderson, Minnesota: With two DWI charges, two drug-possession charges and a driving-with-a-limited-license charge stemming from a Jan. 1 arrest, Henderson is likely radioactive and won't generate much interest unless and until his legal situation is cleared.

Will Smith, New Orleans: A salary cap casualty, Smith missed the 2013 season with a torn ACL and will be 33 in July. He's a more natural fit as a 4-3 end than a 3-4 linebacker, and at 282 pounds will likely draw more interest from those teams.

Jasper Brinkley, Arizona: After starting 15 games for the Vikings in 2012, he started just three last year for the Cardinals. He's a two-down linebacker: a decent run defender who has yet to post his first NFL sack.

OTHERS: Willie Jefferson, Buffalo; Jameel McClain, Baltimore; Stephen Nicholas, Atlanta.

RESTRICTED FREE AGENTS:

Vincent Rey, Cincinnati: The 26-year-old filled in at middle linebacker midway through the season and delivered some solid play, particularly in coverage. He's an ideal top backup, and can play all three linebacker spots in the 4-3.

Albert McClellan, Baltimore: A starter in 2012, McClellan played sparingly in a rotational role last year. He's a typical two-down linebacker who is stout against the run.

Mark Herzlich, Giants:He's made six starts in three seasons with the Giants, and saw more defensive playing time last year than the previous two seasons. But he returned to the bench after a pair of early-season starts this year, and saw sporadic defensive work after that, with most of his repetitions coming on special teams. He may be a backup plan for the Giants if they don't re-sign Beason.

OTHERS: Bryan Braman, Houston; Larry Dean, Minnesota; Phillip Hunt, Philadelphia; Jamari Lattimore, Green Bay; Garrett McIntyre, N.Y. Jets; Spencer Paysinger, N.Y. Giants.