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

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

"I think there's some, those top-end guys that we would like to take a shot at, but I think I said this last year," Quinn said at the NFL Scouting Combine last week. "You look at the list today, and it could be vastly different a week from now because all these franchise guys are getting signed to their tenders and, you know, guys are getting re-signed to their own teams.

"So the list that we're working off might be totally different a week from now, but we've done our research, we've done a lot of work in the last couple months and even back during the season. So I feel we're well-prepared whichever way we go."

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

Dont'a Hightower, LB, New England

The Lions could stand to use more playmakers at the position, even if DeAndre Levy is able to return to form in 2017. Hightower recorded 65 tackles, 2.5 sacks, one forced fumble, two defended passes and a safety last season. He could add instant play-making to Detroit's linebacking corps.

A.J. Bouye, CB, Houston

He started last season as Houston's fourth cornerback, and by the end of the year was playing at a Pro Bowl level. Opponents completed just 54 percent of their passes when throwing at Bouye last season with a 73.1 passer rating and just two touchdowns. Bouye defended 16 passes and picked one off.

Logan Ryan, CB, New England

Ryan is a tough, physical corner that seems to fit the way Lions defensive coordinator Teryl Austin likes to play in the back end. He recorded 92 tackles and also had three quarterback hits, two tackles for loss, a forced fumble, a sack and two interceptions. He doesn't seem to mind sticking his nose in and making a tackle. He also defended 11 passes.

Ricky Wagner, RT, Baltimore

Pro Football Focus graded Wagner among the top eight right tackles in the NFL last season. He's only 27 years old, and allowed just two sacks all season protecting Joe Flacco's right side.

Riley Reiff, T, Detroit

Quinn said at the Combine that he's been in touch with Reiff's representation about getting a new deal done. It will be interesting to see how this year's thin draft class at tackle might push the market up for veteran tackles. Reiff is steady on the right side.

Jabaal Sheard, DE, New England

For a team that recorded just 26 sacks last season, upgrading on the edge could be on Quinn's wish list. This is a very strong draft class of edge rushers, so he has options here. Quinn has some familiarity with Sheard, who's recorded 13 sacks the last two seasons combined.

Zach Brown, LB, Buffalo

In his first season as a starter in Buffalo, Brown racked up 149 tackles (97 solo) and also chipped in four sacks, four passes defended, two forced fumbles and an interception.

Larry Warford, G, Detroit

Warford got over some nagging injuries in 2014 and 2015 to have a nice season in 2016. He's started all 57 games played his first four seasons, and knows Detroit's coaching staff and schemes well.

Paul Worrilow, LB, Atlanta

Worrilow, 26, lost his middle linebacker job to rookie Deion Jones last season, but had 95, 142 and 127 tackles, respectively, from 2013-15 as a starter in Atlanta. He's been productive when given the opportunity to play.

Torrey Smith, WR, San Francisco

At 28, Smith is on the right side of 30, and he can still fly. He's only one year removed from averaging a league-best 20.1 yards per catch in 2015. He caught 20 passes for 267 yards and three scores last season in 12 games.

Johnathan Hankins, DT, New York Giants

Hankins is an athletic big man, who would seem to be a good fit in Austin's attacking, one-gap scheme. He recorded 43 tackles, 10 quarterback hits, eight tackles for loss, three sacks and a forced fumble in New York last season. He could be an athletic 320 pounder to pair with A'Shawn Robinson and Haloti Ngata.

Duron Harmon, DB, New England

Harmon played as the Patriots' third safety this past season, but even as a rotational player, he still managed to get 48 percent of snaps. He's a versatile cover man with size (6-1, 205). He recorded 29 tackles, defended two passes and had an interception and forced fumble.

D.J. Fluker, T/G, Los Angeles Chargers

With Fluker comes flexibility. He can play both guard and right tackle, and he started all 16 games last season. In fact, he's started every game he's played in the last four seasons since being a first-round pick out of Alabama.

Kevin Minter, LB, Arizona

Minter, 26, has been a full-time starter in Arizona the last two seasons, and has recorded 175 tackles over that span. He also had 3.5 sacks last season.

LeGarrette Blount, RB, New England

The Lions need a big, tough back to pair with Ameer Abdullah and Theo Riddick. Blount rushed for 1,161 yards and 18 touchdowns last season. He could add instant toughness to Detroit's backfield.