The permitted window for NFL teams to contact and enter into contract negotiations with player agents is upon us, though no contract can be officially signed until the opening of free agency at 4 p.m. on Wednesday.

Lions general manager Bob Quinn is expected to be active in free agency, but at what level is yet to be determined.

"You look at the free agency list right now and there's a bunch of guys that you like, right?" Quinn said when asked at the Combine about some of the defensive players in particular set to become free agents. "But a lot of these guys are going to re-sign with their own teams before they even get to the open market.

"So, you've got to be able to adjust. You've got to be able to take the players that you have on your team and try to fit them into spots where Matt (Patricia) and the defensive coaches want to use them, and then you kind of just fill in as you go through free agency and the draft."

Here's my list of 15 players who could potentially be a fit with the Lions in free agency:

Dion Lewis, 27, RB, New England

Lewis got a chance to carry a majority of the load for the Patriots' running game last year, and he didn't disappoint. He averaged a terrific 5.0 yards per carry for 896 yards and six touchdowns. He also caught 32 passes for another three scores, and returned a kickoff for a touchdown to give him an even 10 touchdowns on the year.

Nigel Bradham, 28, LB, Philadelphia

Bradham is the kind of wily veteran that can step right into the SAM spot and be a playmaker. He's also versatile enough to shift inside alongside Jarrad Davis in a 3-4 look. He recorded 88 tackles last year, but was the best 4-3 cover linebacker as graded by Pro Football Focus with eight passes defended.

Dontari Poe, 27, DT, Atlanta

At 347 pounds, Poe can anchor the nose in a 3-4, but is also versatile enough to slide over in a 4-3. He's only missed two games over his six-year career, and recorded 38 tackles and 2.5 sacks last year. He earned a positive grade from PFF last season as both a run stopper and pass rusher.

Malcolm Butler, 28, CB, New England

Patricia knows Butler well. He told reporters at the Combine he has a terrific relationship with the veteran cornerback, despite what happened with Butler's benching in the Super Bowl. Butler had 55 tackles, 12 passes defended, two interceptions and three forced fumbles in 16 regular-season games last season.

Isaiah Crowell, 25, RB, Cleveland

Crowell has averaged at least 4.1 yards per carry in three of his first four years in the NFL playing on a team in Cleveland that's won 11 games over his four-year career. He's a tough runner with a career 4.2 yard per carry average and 21 touchdowns.  

Carlos Hyde, 27, RB, San Francisco

Hyde is the kind of power back (6-0, 230) the Lions could be on the lookout for this offseason. It's not out of the realm of possibility that Quinn signs a back in free agency, and also drafts one in the first two days. Hyde rushed for 938 yards and eight touchdowns last year.

Haloti Ngata, 34, DT, Detroit

Ngata still has some juice left. He was playing very well last year before a bicep injury ended his season after just five games. Detroit's run defense took a major dive without him. He's not the player he once was, but he can still be a very productive part of a defensive line rotation. 

Trey Burton, 26, TE, Philadelphia

Burton hasn't had a lot of opportunities in Philadelphia playing behind Zach Ertz, but he's a terrific young player. He had five touchdowns last year, and earned a top 14 grade at the position from PFF with a positive pass-blocking grade as well.  

DaQuan Jones, 26, DT, Tennessee

A versatile defensive lineman at 6-foot-4, 322 pounds. He's a plus run defender, but also got after the quarterback a little bit last season with 3.5 sacks. He can play just about anywhere along a defensive front.

Tahir Whitehead, 27, LB, Detroit

The Lions' leading tackler last season (110), Whitehead can play any linebacker position, and play it well. That's a nice asset to have in a defense that plans to be multiple in 2018. Whitehead is also dependable, as he's missed just one game in the last five years.

Bashaud Breeland, 26, CB, Washington

He's one of the more productive cornerbacks to hit the market in his prime. He's played in 60 games (57 starts) over his first four years with 270 tackles, 60 passes defended and eight interceptions. He defended 19 passes last season. Teams completed less than half of their passes thrown his way in 2017.

Bennie Logan, 28, DT, Kansas City

A better run defender than pass rusher, Logan recorded 52 tackles from the interior last year with 1.5 sacks. He's posted at least 50 tackles in three of the last four years.

Adrian Clayborn, 29, DE, Atlanta

Sure, six of Clayborn's 9.5 sacks last year came in one game against Dallas, but the veteran pass rusher also earned a positive grade from PFF in 12 of 16 games, and finished in the top 15 in quarterback hurries (37) among defensive ends. That was one fewer than Everson Griffen's 38.

Jimmy Graham, 31, TE, Seattle

Graham's catches, yards and average yards per catch numbers were very similar to Eric Ebron's last year, but where Graham had a distinct advantage is in the touchdown department (10). Graham is still one of the best red zone weapons in the NFL.

T.J. Carrie, 27, CB, Oakland

Carrie is a veteran nickel cornerback with good length (6-0, 205), who recorded 84 tackles last season with nine passes defended. If Quandre Diggs' move to safety is permanent, the Lions will be looking for a new nickel cornerback this season. Second-year cornerback Jamal Agnew is a candidate, but teams can never have too many options.