This is the seventh in an eight-part series reviewing the 2016 Vikings and looking ahead by position. Previously: OL / RB, TE / WR / QB / DL / LB

For the first time since Mike Zimmer gutted the Vikings' defensive roster upon arrival in 2014, the defense could see some significant turnover. Most of which may come from a strong cornerback group, where slot man Captain Munnerlyn and Terence Newman are pending free agents.

In the back end, safety play became an issue after the Vikings' 5-0 start with injuries forcing young players into prominent roles. Harrison Smith had a down year to his standards while playing through a severe ankle injury for a few games. Despite that, the Vikings allowed just one 300-yard passer all season.

Cornerbacks

Under contract in 2017: Xavier Rhodes, Trae Waynes, Mackensie Alexander, Marcus Sherels, Jabari Price, Tre Roberson

Pending free agents: Captain Munnerlyn, Terence Newman

Safeties

Under contract in 2017: Harrison Smith, Andrew Sendejo, Anthony Harris, Jayron Kearse, Antone Exum Jr., Cedric Thompson

Pending free agents: None

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Grades are based on a 1-5 scale, with '5′ marking an excellent season, '4′ for above-average, '3′ for average, '2′ for below-average and '1′ for failure to perform. Players who 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. Based on game and practice observations, weekly film reviews and interviews. Missed tackles provided by Pro Football Focus analyst Trevor Lynch.

Xavier Rhodes (4.0): In his fourth NFL season, Rhodes put himself on track for a lucrative multi-year extension as an ascending No. 1 corner. Named to his first Pro Bowl. Played 786 snaps [75.9%], becoming the first Vikings cornerback with five interceptions (a career best) since Brian Williams in 2003. Missed the first two games due to a knee injury suffered in warmups in Tennessee. Leveled out his play and rose to the occasion in big games. Trailed top receivers in Odell Beckham Jr., DeAndre Hopkins and Dez Bryant, helping hold each to five catches or fewer. Tied the team lead with 11 deflections. Scored his first career touchdown on a 100-yard interception return off Carson Palmer, a critical play in the Vikings' Week 11 win. Forced a fumble in Philadelphia. Long, pesky defender in coverage, which still gets him into trouble. Led the team with eight penalties (down from 10), including three in Jacksonville. His poor game vs. the Jaguars included Marqise Lee's 100-yard game, the first such game vs. the Vikings by a WR, and a $12,154 fine after an outburst following a holding call on him. Inflamed the 'miscommunication' at Lambeau by telling reporters defensive backs had planned in the week to go against Mike Zimmer's game plan to have him shadow Jordy Nelson. Part of a sure-tackling cornerback group with just four misses, though one included Golden Tate's game-winning touchdown in the overtime loss to the Lions. Entering a contract year on a fifth-year option. The Vikings have previously locked up key young players before they enter their contract season.

Terence Newman (4.0): Played an impressive 752 snaps [72.7%] as the oldest cornerback in the league by five years at age 38. Started the first eight games before Trae Waynes took the lead at left cornerback in the second half of the season. Started 10 games overall, missing one due to a neck injury. Continually making up for lost steps by rarely being caught out of position. An anchor in a cornerback group that was often avoided by quarterbacks and didn't allow a 100-yard wide receiver until Week 14. Fourth on the team with eight deflections. Intercepted Cam Newton in the Vikings' Week 3 win. Missed four tackles (down from six). Appeared to spearhead a diversion that was later called a miscommunication at Lambeau. Newman told Zimmer on the sideline he also wanted to cover Nelson, instead of the game plan to have Rhodes shadow him, according to Zimmer. Nelson blew up for a season-high 154 yards allowed by the Vikings as he caught a pass against nearly every member of the secondary. Flagged four times. Looks like he could play a 15th NFL season next fall if he wanted, though Waynes is expected to continue his starting role in Minnesota. Vikings' nominee for the Art Rooney Sportsmanship Award. A pending free agent.

Captain Munnerlyn (3.5): Holding down the slot duty for a third season with the Vikings, Munnerlyn likely earned himself a decent payday in a contract season. Played 637 snaps [61.5%] in the often-used nickel defense, limiting the impact of opposing slot receivers. Dealt with a nagging ankle injury that held him out of much of the Nov. 6 overtime loss to the Lions, when Anquan Boldin caught a touchdown from the slot vs. Mackensie Alexander. Missed his only game the following week at Washington. Returned to force a fumble and hold Larry Fitzgerald to 63 yards in the Week 11 win. Went without an interception for the first time since 2011. Beat by Boldin for a critical 29-yard gain on third down, which help set up the Lions' game-tying field goal in the Thanksgiving loss. Deflected three passes. Flagged twice. Missed three tackles. Given the Korey Stringer Media Good Guy Award for a consecutive season. Turns 29 in April. Pending free agent likely to test the market.

Trae Waynes (3.0): The former 11th-overall pick was thrown into the starting lineup at the start of his second NFL season when Rhodes injured his knee during warmups in Tennessee. Struggled out of the gate against both Titans receivers Tajae Sharpe and Andre Johnson. Had a rough go the following week, when he was flagged three times and surrendered a touchdown vs. Green Bay. Helped seal the win with an interception. Missed one game due to a concussion. Played 579 snaps [55.9%] and showed off his disruptive potential. Tied the team lead with 11 pass deflections. His three interceptions trailed only Rhodes on the team. Displayed growing pains as he was flagged seven times, including a team-worst four pass interference calls. The defense's most efficient tackler, missing only one. Allowed a touchdown on a scramble to Boldin in the Thanksgiving loss. Then he later prevented a touchdown with a diving deflection vs. Marvin Jones. Wanted a push-off, but got no call on Davante Adams' 20-yard touchdown in the Week 16 loss. Still playing through inconsistencies of a young player while showing promise.

Marcus Sherels (3.0): The Vikings' reliable punt returner was missed as he was forced out of five games due to busted ribs and a wrist injury, marking the first time he needed to sit since he became the Vikings' returner in 2011. Just missed out on a $100,000 bonus after the Chiefs' Tyreek Hill scored a 95-yard return for a touchdown in the season finale, vaulting him ahead of Sherels to lead the NFL in punt return average. Scored a career-best two touchdowns on returns against the Panthers and Texans. Finished second in the NFL with 13.9 yards per punt return, the second-best mark of his career. Played four snaps on defense [0.4%].

Mackensie Alexander (2.0): Drafted in the second round (54th overall) out of Clemson and showed he has improvements to make should the Vikings trust him to take over for Munnerlyn in the slot. Allowed a touchdown and was flagged three times on 68 snaps [6.6%]. Jumped in for an injured Munnerlyn against the Lions and was replaced by Newman after 18 snaps.

Jabari Price (N/A): Spent the season on injured reserve due to a knee injury suffered during the preseason finale. The former seventh-round pick is entering the final year of his rookie contract.

Tre Roberson (N/A): The converted college quarterback signed as an undrafted free agent and was thrice released and re-signed to the practice squad. Inked a reserve/future deal.

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Harrison Smith (3.5): Had a quiet season to his lofty standards, going without an interception for the first time in his NFL career. Had an interception negated by a teammate's penalty in the season-opening win vs. Marcus Mariota. Signed a lucrative five-year extension last summer guaranteeing him nearly $29 million against injury through the 2018 season. Led the secondary with 893 snaps [86.3%], many while gutting through a severe ankle sprain suffered in November. Missed two games and struggled in his return at Lambeau, allowing a touchdown to Jordy Nelson. Second on the team with 91 combined tackles. Deflected two passes, including a dropped potential pick six off Eli Manning in the Week 4 win. Bit on a double move and was the culprit on Dez Bryant's 56-yard catch in the Dec. 1 loss to Dallas. Missed 11 tackles (up from seven), including on Golden Tate's game-winning touchdown in the overtime loss. Named to his second Pro Bowl. Flagged once for roughing the kicker, which led to a successful two-point conversion by the Eagles. Still one of the most versatile safeties in the league as a valuable pass and run defender. Chipped in two sacks on 45 blitzes. Said he won't need offseason surgery on his injured ankle.

Andrew Sendejo (3.0): Warded off competition again to remain the Vikings starter alongside Smith after signing a four-year extension worth up to $16 million with no guaranteed money beyond 2016. Played 855 snaps [82.6%]. Like Rhodes, Sendejo turned previous drops into picks with a career-best two interceptions and four deflections. Fifth on the team with 69 combined tackles, but tied for second with 11 misses (down from 12), including one of several to miss on Robert Turbin's touchdown run in the Week 15 loss to the Colts. Beat by Philip Dorsett for a 50-yard touchdown in the same game. Landed on injured reserve with a knee injury after the following week's loss at Lambeau. Missed two games. Remained a special teams contributor with 133 snaps [31%].

Anthony Harris (2.0): Played 234 snaps [22.6%] and started three games in the final month after injuries held back Smith and Sendejo. Showed promise as a run defender with 15 combined tackles in the loss to the Colts, but was a frequent target for Andrew Luck. Surrendered a 31-yard gain to T.Y. Hilton that helped set up the Colts' first touchdown. Flagged once on special teams. Deflected one pass. Recovered a fumble in the season finale win vs. the Bears. A core special teams contributor with 277 snaps.

Jayron Kearse (2.0): Drafted in the seventh round (244th overall) out of Clemson. Saw his first extended action in Philadelphia, playing 52 snaps after Sendejo was injured. Made his NFL start the next week in Chicago, where he was pulled quickly after taking a bad angle on Jordan Howard's 69-yard run. Played 78 defensive snaps [7.5%] and 247 snaps on special teams. Flagged twice.

Antone Exum Jr. (N/A): Placed on injured reserve to start the season after injuring his leg in the preseason. The former sixth-round pick is entering the final year of his rookie contract.

Cedric Thompson (N/A): Signed twice to the practice squad, initially joining in late October after Sendejo's ankle injury. The ex-Gophers defensive back inked a reserve/future deal.