At the center of the Vikings' defensive issues to begin 2018 were a pair of linebackers either running toward or put into the wrong places at the wrong times. Anthony Barr and Eric Kendricks, a proven duo, rebounded unevenly as head coach Mike Zimmer tinkered with a defense that had play-action problems but would once again force the NFL's stingiest third-down rate and fewest touchdown passes.

And Barr might have played his last game in a Vikings uniform. That game, on Dec. 30 against Chicago, was the type of quiet outing that has puzzled insiders and outsiders five seasons into Barr's career.

Grades are based on a 1-to-5 scale, with '5' marking excellence, '4' for above-average, '3' for average, '2' for below-average and '1' for failure to perform. Players that did not accrue a season (weren't on the active roster for at least six weeks) or played in three games or fewer are not graded. Below are individual grades, based on game and practice observations, weekly film reviews and interviews with coaches, for seven linebackers who finished the season on the Vikings' active roster, injured reserve or practice squad. Unofficial NFL stats, such as QB pressures, missed tackles and targeted passes, are compiled by

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Anthony Barr (3.5) — Quiet, or sometimes poor, games bookended Barr's otherwise impactful contract season. It's the inconsistency frustrating his biggest fans inside and outside Vikings headquarters. Played 808 snaps [77.8%]. Received one All-Pro vote. Had eight tackles for losses, two deflections and a forced fumble. A hard-hitting force, making it worth wondering how he could fare in a system allowing more chances. Said game plans catered to his strengths later in the season. That included blitzing. A summer of pass-rushing drills paid off as Barr was one of the NFL's most effective blitzing linebackers with 23 QB pressures on 94 rushes. Three sacks were the most since 2015, two essentially unblocked (at SEA, vs. MIA). Had a third-down sack negated by penalty in the season finale vs. Chicago. Didn't see many blitzes to the end with one credited hit to 19 hurries.

Penalized twice, both on Bills touchdown drives in the Week 3 loss. At times victim of poor scheme and situations in coverage. Caught on three touchdowns in the Week 4 loss at Los Angeles. Cooper Kupp's 70-yarder came as safety Harrison Smith played the screen, forgoing any help he could offer. Barr was a step behind Todd Gurley's eight-yard touchdown catch. Said he didn't have rapport with rookie corner Holton Hill to switch assignments before Robert Woods' 31-yard touchdown (as seen below). The Rams motion into an empty backfield with Hill ending up on Gurley and Barr mismatched on Woods. a David Johnson fumble and deflected a third-down Josh Rosen pass in the Week 6 win vs. Arizona. Missed three games, ending his defense-leading 44-start streak, due to a hamstring injury suffered in New York. Like Kendricks, Barr had a subpar game in New England where he was beat on a 15-yard jet sweep to Julian Edelman and a 9-yard James Develin catch. Bounced back with three sacks in back-to-back games against the Seahawks and Dolphins. Knifed into the backfield on a third-and-1 run stop in Seattle (seen below). Watch the force with which Barr breezes past the Seahawks' 322-pound George Fant for this stop. three more stops against the Lions in Week 16. Then finished with a whimper against the Bears with one assisted tackle while Chicago ran for 169 yards. His lone highlight of Week 17 was undercutting the fullback on a 1-yard run by Jordan Howard. Barr's impact was obvious in most games, but the Vikings defense didn't necessarily suffer in his absence. Missed four tackles all season. Pending free agent.

More reading: Anthony Barr, secure in himself and his play, is ready to cash in with or without the Vikings

Eric Kendricks (3.0) — Tied a franchise record with his fourth straight season as Vikings leading tackler to start his career. Did so after signing a five-year, $50 million extension in April and despite missing the final two games due to a hamstring injury. Played 875 snaps [84.2%]. Received one All-Pro vote. An efficient tackler in tight or open spaces, Kendricks typically only got into trouble when he was overpowered in the run game. Seemed to struggle in coverage. Pegged with the most yards allowed after the catch (476) of any linebacker by Pro Football Focus. Much of that likely includes the many reversing running backs or tight ends that beat the Vikings' schemes through play action early in the season. Had seven pass deflections and six tackles for losses, including one sack. Led Vikings linebackers with 22 run stops, but that ranked 35th in the NFL. Uneven season from Week 1, when Kendricks deflected a third-down pass to George Kittle and stuffed Alfred Morris at the 1-yard line. Then watched Kittle sneak by him for gains of 18 and 36 yards. Evaded Jason Peters and recovered a Jay Ajayi fumble at the goal line in Philadelphia. Later a step behind and beat on a 12-yard touchdown catch by Wendell Smallwood. Made three run stops against the Saints, but was beat by Alvin Kamara on a 17-yard catch and run to set up a 1-yard touchdown run. Had a career-high two interceptions, catching Russell Wilson's attempted throwaway in the red zone before halftime to keep Seattle's lead to 3-0. Posted 16 combined tackles and an interception in New England, but was a step behind Patriots backs in critical plays, including James White on a third-and-3 down in the red zone. Played through a rib injury in New England and Seattle. Penalized twice. Missed seven tackles.

Eric Wilson (2.5) — Wilson added 15 pounds of muscle entering his second NFL season, in return came opportunities. Earned roles as a primary backup and subpackage linebacker in his second NFL training camp. Started four games for both Barr and Kendricks. Played 336 defensive snaps [32.3%]. Had 4 1/2 tackles for a loss, including two sacks. Played a big game near his hometown of Redford, Mich. with both sacks and a tackle for a four-yard loss in Detroit. Showed a learning curve that coaches see similar to Kendricks. Had a tendency to overrun his assigned gap, leaving holes. Couldn't chase down Alvin Kamara on a jet sweep for a 3-yard touchdown. Had a hard time fighting through Bears blockers in the finale, ceding gains of eight and 11 yards his way. Flashed potential as a reliable reserve moving forward, meaning the Vikings would likely bring in competition if Barr doesn't return. Missed six tackles all season. Penalized twice.

Ben Gedeon (2.5) — Gedeon kept his role at weak-side linebacker in the Vikings base defense and ceded some subpackage work to Wilson in his second NFL season. Played 310 defensive snaps [29.8%]. Missed Nov. 25 vs. the Packers due to a concussion. Despite his role in run situations, Gedeon was often blocked out of the play. Did not have a tackle for a loss. Had nine run stops. Showed flashes in coverage, deflecting a pass intended for tight end Jimmy Graham in the Week 2 tie at Green Bay. A reliable player, if outmatched at times. Led the team with 334 special teams snaps. Missed one tackle. Did not draw a flag.

Kentrell Brothers (2.0) — Served a four-game suspension for performance-enhancing drugs to start the season. Had nine tackles in 202 special teams snaps through 12 games. Played five defensive snaps. Got first career sack at end of Week 16 win vs. Detroit.

Devante Downs (2.0) — Drafted in the seventh round (225th overall) out of Cal. Recovered from second torn ACL and earned a roster spot in two preseason games. Played 125 special teams snaps in 11 games.

Reshard Cliett (N/A) — Fourth-year veteran signed with Vikings in free agency. Lost preseason battle on depth chart to rookie Devante Downs and spent year on practice squad. One of 10 practice squad players to sign a futures contract on Jan. 2.