Jets head coach Aaron Glenn brings impeccable defensive credentials to his new job and to one of his old teams. He and general manager Darren Mougey wasted no time in free agency addressing the team's needs on defense.

The first order of business was the re-signing of their own unrestricted free agent, middle linebacker Jamien Sherwood who had a breakout season in his fourth year with the Green & White. After re-signing Sherwood (and DB Isaiah Oliver) Glenn and Mougey turned their attention to beefing up the interior defensive line and the defensive backfield.

"We're looking for winners," Glenn said at last month's NFL Combine. "We're looking for smart, tough, aggressive and resilient players. We're going to do everything we can to find those guys, and you can find them in all different spots — small schools, big-time schools, trades. Wherever we can find them, we're going to try to bring them on this team."

It is worth noting that 9 of the 13 most recognizable free agents the Jets signed in March are 27 years old or younger. None are 30 or older.

Mougey added at the Combine: "Every decision AG and I make since we've gotten here and moving forward is with the goal of winning now and from now on."

The following is a look at the Jets' defensive moves to date, including three players (LBs Sherwood and Jamin Davis, plus DB Oliver) who re-signed with the Green & White before hitting the open market:

LB: Jamien Sherwood, Jamin Davis
The Fit: Keeping Sherwood, 25, in green and white, and as the Mike LB was one of the Jets' top priorities, signing him to a lucrative, long-term deal days before the official opening of free agency. With C.J. Mosley limited to two games last season because of injury, Sherwood (6-2, 202), drafted by the Jets in the fifth round in 2021 after playing safety at Auburn, took full advantage of his opportunity. In 17 games (16 starts), he tied for the NFL lead in solo tackles (95) and tied for fourth with a career-high total takedowns (154). He added 10 TFL, 3 PD and a pair of sacks.

The Room: Sherwood and incumbent Quincy Williams, 28, are the only returning LBs to see significant playing time last season. The Jets retained Jamin Davis, 26, a waiver claim last year from Minnesota, who was a first-round draft pick (No. 19 overall) by Washington in 2021. Sam Eguavoen, 32, is a free agent and remains on the market.

The Future: The fact is, there's plenty of room in the room and defensive coordinator Steve Wilks will oversee an open competition while seeking depth -- which could come from the draft or the development of players like Zaire Barnes, 25.

DB: Isaiah Oliver, Brandon Stephens, Andre Cisco, Kris Boyd
The Fit: The versatile Oliver, 28, played in every game -- and every position in the secondary: safety, cornerback, nickel and dime --last season in his first year with the Jets. Oliver (6-0, 202) started 7 games, made 57 tackles, had 3 passes defensed and a sack. He was selected by Atlanta in the second round (No. 58 overall) of the 2018 NFL Draft and spent his first five seasons with the Falcons before moving to San Francisco for the 2023 season. He signed with the Jets last March after being released by the Niners. In his career, he's appeared in 75 games (43 starts) with 256 tackles (187 solo) and 3 INT.

Stephens, 27, was signed in the hope he would grab the CB2 spot opposite Sauce Gardner. Stephens (6-1, 216), the first defensive player the Jets signed in free agency this year, has good size and played in all 17 games in two of his four seasons in Baltimore. Overall, he started 37 of the Ravens' 39 games the last two seasons, including 4 playoff games. He totaled 144 tackles, 2 interceptions and 21 pass defenses.

Cisco, 24, is a Long Island native and free safety who played in college at Syracuse and is capable of fitting in a Cover-1 scheme often favored by HC Aaron Glenn. Cisco (6-0, 209), who signed a one-year deal after four years with Jacksonville, had a passer rating as the nearest defender (79.2) ranked 18th out of 70 safeties (min. 250 coverage snaps), according to Next Gen Stats.

Boyd, 28, is seen as more akin to the Jets' former special teams ace Justin Hardee. Boyd (5-11, 201), like Hardee and current Jets player Irvin Charles (who is coming back from an ACL injury), is a gunner on the punt-coverage team. With his speed -- he was clocked at 22.32 mph last season on a punt, per GPS tracking -- Boyd could be a key cog in the important field-position game.

The Room: Gone from last season's team are CB D.J. Reed (Detroit) CB Brandin Echols (Pittsburgh) and S Ashtyn Davis (Miami). CB Sauce Gardner, slot Michael Carter II, S Tony Adams and CB Qwan'tez Stiggers are the main holdovers. Carter, who has been solid in the slot, was limited to 13 games last season as he dealt with a nagging back injury. Gardner, entering his fourth season with the Jets, will be looking to reassert his dominance in HC Aaron Glenn's revamped defensive backfield.

The Future: With so many spots to fill, the Jets moved quickly in free agency, adding experienced players in S Cisco, CB Stephens and CB Boyd (who also adds speed and depth on special teams after Echols' exit). The Jets believe Stephens could team with Gardner for the foreseeable future. Still, adding depth is likely to be a priority in April's NFL Draft.

DL: Byron Cowart, Derrick Nnadi, Jay Tufele, Rashad Weaver
The Fit: Giving Pro Bowl DT Quinnen Williams help in the middle of the defensive line is one of the priorities this offseason. Cowart, 28, has been around the block during his NFL career, spending a couple of seasons with New England, missing the 2021 season due to injury, playing all 17 games for Indianapolis in 2022 after being waived by the Patriots, signing and being released by Kansas City and then Houston, and a season on Miami's practice squad before landing with the Bears. Cowart (6-3, 300) moved from the practice squad to the active roster in early October and is being reunited with Chicago's former D-line coach Eric Washington.

Nnadi, 28, has three Super Bowl rings he won while playing all seven of his NFL seasons for the Chiefs. At 6-1, 300 he's another wide body that will help the Jets' defense in the run game while also fitting in on a rotation along the D-line. During his time with KC Nnadi played 3,063 defensive snaps in 115 games (87 starts) and had 233 tackles and 5 sacks in regular season play.

Tufele, 25, last season had a career high 243 snaps playing in 13 games (the most of his career) last season for the Bengals. At 6-3, 305, he's more of a run stuffer than pass rusher (he has only a half-sack across four NFL seasons). He was selected by Jacksonville in the fourth round of the 2021 NFL Draft.

Weaver, 27, saw action as a linebacker the past three seasons, two with Tennessee and last season briefly with Houston (he was released in November). At 6-4, 259, he's big enough and quick enough to be penciled in as a defensive end, spelling Jermaine Johnson and Will McDonald IV, both of whom are also comfortable and productive playing off the line as LBs. Weaver had his best season in 2022 when he played in 16 games (4 starts) and made 27 tackles (18 solo), 7 TFL, 5.5 sacks, 6 passes defended, 2 FF and a fumble recovery. He shifted to OLB in 2023, playing in 15 games with 20 tackles (11 solo), 4 TFL and a pass defended.

The Room: Javon Kinlaw (Commanders) and Solomon Thomas (Cowboys) left the Jets in free agency while Leki Fotu remains available. Other than Williams, the Jets were thin on the interior D-line. Leonard Taylor III returns for his second season.

The Future: Though the Jets have added three players on the interior of the defensive line in free agency, analysts have called this year's crop in the NFL Draft one of the best in years. With eight picks overall and No. 7 (at present) in the first round, adding another wide body up front is a definite possibility.