On the roster: Tracy Walker, DeShon Elliott, Kerby Joseph, C.J. Moore, Brady Breeze, JuJu Hughes

Key losses: Dean Marlowe

^with another team *college stats

Best competition: Starter next to Walker

The Lions and Walker agreed to a three-year extension through the 2024 season, making Walker a team leader and key player in the Lions' rebuild.

Now the next job for head coach Dan Campbell and defensive coordinator Aaron Glenn is finding Walker a running mate.

Elliott got a lot of those reps in the spring and he'll likely get first crack at the starting spot next to Walker when camp kicks off next week. In 16 starts with the Ravens in 2020, Elliott racked up 80 tackles, three tackles for loss, 2.5 sacks, two forced fumbles and four defended passes. He started six games last year before a torn bicep landed him on IR and ended his season.

Elliott is versatile in that he can play in the box, but also cover and rush. He could be a really nice complement to Walker in Detroit's split-safety defense.

The rookie Joseph could throw his hat into the ring in camp too. He's a ball hawk, which was evident by his five picks at Illinois last year. He's a converted receiver, so he's got good hands. How quickly he can make the jump to the speed of the NFL game will go a long way in determining how early and how often he can get on the field.

Two other players to watch out for at safety are Will Harris and Ifeatu Melifonwu. Harris was playing mostly cornerback in OTAs and minicamp, but he has experience at safety and could be a matchup player for Glenn in the dime or a three-safety sub package. The Lions love Melifonwu's size (6-3), and he was working at both corner and safety in the spring.

Moore is a terrific special teamer, and he can also step in and play on defense.

Twentyman's take: Walker is a good young player with a versatile skillset, but better ball production is really going to make a big difference for him. Walker had some chances for a few more interceptions last season, but let them slip through his grasp. It's been a focus for both him and defensive backs coach Aubrey Pleasant this offseason.

Elliott was an under-the-radar signing that I think will pay dividends in Detroit. He's been a starter the last two seasons for one of the most consistent defenses in the league, and that's what he brings most to the Lions' defense – consistency. He's kind of a do-it-all safety, and I think that will play well next to Walker in Glenn's defense.

The Lions allowed 59 completions of 20-plus yards last season, and opposing quarterbacks had a passer rating of 96.5 on attempts that traveled at least 21 yards in the air. That's an area where Detroit has to be better defensively, along with their overall team tackling.

The safeties in Glenn's defense are not only the last line of defense, but they're also tasked with being playmakers. The Lions need more difference-making plays from Walker, Elliott and the rest of that unit if this defense is going to take the next step.

Walker was the Week 18 NFC Defensive Player of the Week after he tallied 13 tackles and a game-sealing interception in Detroit's 37-30 win over Green Bay. The Lions are looking to get more of those performances from Walker in 2022.

By the numbers:

5: Interceptions last year for Joseph in his first full year as a starter for the Illini.

14: Opponent rushing plays of 20-plus yards in 2021, tied for the fourth most in the NFL.

14: Career tackles for loss for Walker, third most by a Lions defensive back in team history.

49: Elliott blitzed 49 times for the Ravens in 16 games in 2020. Don't be surprised if that's part of his game here in Detroit.

105: Total tackles by Walker last season to lead the Lions. It was his second straight season with at least 100 tackles. He was one of only five safeties in the NFL last year with at least 100 tackles, one interception and one sack.

Quotable: "I like the way DeShon approaches his work," Walker said in June. "He approaches his craft each and every day like he wants to get better and he wants to be great, which is very admiring. As far as us two, man, we're out here grinding each and every day and we're trying to bring the young guys up with us. We are just trying each and every day to get better. That's the main thing for us."