Richardson showed flashes of brilliance in pass-rush situations after moving from the Jets to the Seahawks last year. He still possesses the rare ability to generate pressure by working through opposing interior offensive linemen and without help from teammates. That skill is why he could get franchised by the Seahawks. (Bill Kostroun/AP Images)

Players of Poe's body type tend to age fast, so as he heads into his seventh season, Poe might be left to seek out another one-year deal similar to the one the Falcons gave him last year -- or, at most, a two-year contract. (Al Tielemans/AP Images)

The Panthers have a similar issue with Lotulelei as they do with guard Andrew Norwell: Do they make another heavy investment in a position group where they already have at least one player on a massive contract? Carolina extended Kawann Short last year and has former first-round pick Vernon Butler working his way up to more playing time, which could leave little room for a big deal for Lotulelei. (Phelan Ebenhack/AP Images)

Even after the reported trade of Alex Smith that is expected to be consummated at the start of the new league year, Kansas City is still in a cap crunch that could prevent them from retaining Logan, whose solid work against the run ensured that the Chiefs did not miss Dontari Poe too much last year. Logan is only a two-down player, but he handles that role well. (Ed Zurga/AP Images)

If Williams were to move on from Buffalo to a 3-4 team, he would likely project as a defensive end. Most of Williams' work is done against the run, although he did notch 49 quarterback hurries -- according to Pro Football Focus -- and eight sacks over the last two seasons. Williams has only played for the Bills during his 12-season career. (Rich Barnes/AP Images)

A solid presence against the run, the 322-pound Jones saw his 2017 season end four games early because of a torn biceps muscle. In addition to his work as a run defender, Jones has contributed five sacks over the last two seasons. (Darron Cummings/AP Images)

Credited by Pro Football Focus with 20 hurries and nine quarterback hits last year, the former NFL Europa, Arena Football League and Canadian Football League defensive lineman played well during his three-year contract with the Vikings after moving over from the Saints. He advanced from a rotational role in his previous years to become a starter last year, starting more games in 2017 (15) than he did in the previous six seasons of his NFL career combined (10). (Peter Read Miller/AP Images)

In the Rams' 4-3 scheme, the former New England first-round pick was a backup to Aaron Donald before tearing his ACL during training camp last year. Knee problems have dogged him throughout his career, but he has enough talent and explosiveness to merit a buy-low contract. (Jae C. Hong/AP Images)

The Eagles' cap crunch makes it likely that they move on from Allen. A stout run defender who has played above his seventh-round pedigree, Allen started eight games over the last three seasons and has missed just one game in his four-season career. Allen has provided depth behind Fletcher Cox and Tim Jernigan, but he looks worthy of a starting role, something that the Eagles cannot provide. (Nick Wass/AP Images)

At 34 years old and with 13 previous seasons of experience, there are questions as to how much Ngata has left, especially after a torn biceps ended his 2017 season after five games. Ngata is a two-down run defender at this point, and that could limit his value. (Paul Sancya/AP Images)