We got a bit of rare June transactional news last week when the Browns signed free-agent linebacker Mychal Kendricks to a one-year, $3.5 million deal. The 27-year-old veteran, who started 13 games for the Eagles last season before being released in May for salary cap reasons, brings versatility and experience to Cleveland’s new-look defense—and the move supplied the surprising realization that Cleveland’s stronger than many may think at the linebacker spot heading into 2018.

What other units are still flying under the radar or bristling with untapped potential? Looking at offseason free-agency additions, draft picks, and the development arc of a few promising young players—or a little bit of all three—I put together a list of a few of the league’s most underrated position groups.

Bears Secondary

Most of the hype around the Bears’ eventful offseason has focused on the team’s new head coach, Matt Nagy, its offensive skill-position reboot (headlined by the signing of Allen Robinson), and the potential growth of second-year quarterback Mitchell Trubisky. But don’t lose sight of what the team did to keep its burgeoning secondary intact.

After slapping him with a transition tag, the Bears signed breakout star Kyle Fuller to a four-year, $56 million extension; he’s expected to remain the team’s shutdown corner after breaking up 22 passes (third in the NFL) and picking off two balls while allowing an opposing passer rating of just 69.0 (14th) in 2017, per PFF. The Bears also re-signed veteran starter Prince Amukamara to a three-year, $27 million deal and then retained slot corner Bryce Callahan with a restricted-free-agent tender. That trio is set to play alongside one of Pro Football Focus’s top-rated safeties in Adrian Amos and Eddie Jackson, who flashed as a rookie, registering two picks and six passes defensed last year.

The Bears are going to need to get more from their pass rush next year, and the team’s defensive backs will simply have to make more plays on the ball after intercepting just eight passes all of last year (tied for 29th). But Chicago’s unheralded secondary unit looks poised for more recognition in 2018.

Lions Offensive Line

Detroit’s offensive line probably would’ve been on this list at this time last year, too, but injuries derailed a potential step forward: Left tackle Taylor Decker missed half of the season with a shoulder injury, center Travis Swanson missed five games (he subsequently left in free agency), and big-ticket free-agent additions in T.J. Lang and Rick Wagner each missed three apiece, leaving Graham Glasgow as the only opening-game starter to play in all 16 matchups. However, 2018 provides a clean slate for Decker, Lang, and Wagner, and with the free-agency acquisition of guard Kenny Wiggins and the first-round selection of center Frank Ragnow, the Lions’ line is deeper and more talented than it’s been in years.

Ragnow could be the biggest catalyst for a breakout year—especially in the team’s ground game. The 20th overall pick is a nice piece of injury insurance to the interior line because of his versatility to play both guard or center (he’s been playing left guard in minicamp), and at either spot, should provide just the type of tenacity and technical consistency in the ground game that the Lions have sorely missed over the past few years. Detroit finished last in run blocking last year, per Football Outsiders—but if this group can stay healthy, expect big strides in 2018.

Dolphins Secondary

Last year, the Dolphins’ defensive backfield mostly struggled, but the pieces for a breakthrough in 2018 are there. Thirty-year-old Pro Bowl safety Reshad Jones returns as the team’s veteran leader and should benefit from playing a full season next to T.J. McDonald, who missed eight games last year after violating the NFL’s substance-abuse policy. That duo will be flanked by promising corner Xavien Howard (who showcased what he can do in the team’s shocking Monday Night Football win over the Patriots last year by picking off Tom Brady twice) and some combination of Cordrea Tankersley, Tony Lippett, and Bobby McCain (who just became the league’s highest-paid nickel corner with a four-year, $27 million extension).

The key to it all, though, could be versatile rookie safety Minkah Fitzpatrick, who the Dolphins chose with the 11th overall pick. The former Crimson Tide star is set to play everywhere in Miami’s scheme. Fitzpatrick is like a bigger, stronger version of Tyrann Mathieu—rotating in at free safety, strong safety, slot cornerback, and maybe even at linebacker—and brings the type of ball skills the Dolphins’ pass defense has missed. Miami needs its young cadre of corners to take a step forward in their development, but on paper, this looks like a unit we could be sleeping on for 2018.

Titans Secondary

Tennessee’s rebuilt the core of its secondary over the past few years, and could start to see the fruits of its labor, both in free agency and the draft, this upcoming season. The team’s big-ticket move in free agency was to sign Malcolm Butler to a five-year, $61.25 million contract, reuniting him with former Patriots secondary-mate Logan Ryan. Together with 2017 first-round corner Adoree’ Jackson, Tennessee now has a backfield trio with the versatility and talent to match up with all types of opposing pass catchers. Butler’s presence as a reliable shutdown-caliber corner on the outside opposite Jackson should allow Ryan to play more in the slot, where he’s shown he can be effective in coverage while being utilized as an effective situational blitzer.

That trifecta will be bolstered by rangy All-Pro safety Kevin Byard (a third-rounder from 2016 who led the NFL with eight picks last year) and veteran Johnathan Cyprien. Under new defensive coordinator Dean Pees, Tennessee’s secondary has, at least on paper, the makings of a top group in 2018.

Redskins Defensive Line

I really can’t think of a better word to describe what I expect the Redskins’ defensive front to be this year other than, simply, badass. They might not get the most sacks, they might not be the most explosive group, but a defensive line that pairs second-year pro Jonathan Allen with former Alabama teammate and rookie Da’Ron Payne is going to be a pain (both literally and figuratively) for offensive linemen. That disruptive duo should draw plenty of attention on each snap, giving defensive tackle Matt Ioannidis, veteran Stacy McGee, and rookie Tim Settle―who is not a small human at 6-foot-3 and 329 pounds―the opportunity to shine.

On the edge, Ryan Kerrigan (13.0 sacks, three forced fumbles, one pick) remains the pass-rushing rock, Preston Smith (8.0 sacks) has breakout-star potential, and Anthony Lanier (5.0 sacks) will look to build off last year’s promising campaign. Add in second-year linebacker Ryan Anderson (who may play a little bit inside), veterans Pernell McPhee and Ziggy Hood, and Washington’s built a deep, versatile, and physical front.

Browns Linebackers

Let’s finish up where we started off. Cleveland’s linebacker corps is headlined by former All-Pro Jamie Collins and Christian Kirksey (both of whom got long-term extensions from the team last year), and also includes a quiet Pro Bowler in 24-year-old middle linebacker Joe Schobert, who broke out last year to tie for the league lead with 144 tackles. Add in depth players like James Burgess (who started nine games when Collins missed time to injury) and fifth-round rookie Genard Avery, and defensive coordinator Gregg Williams should have plenty of options at the position.

Kendricks got high marks from Pro Football Focus in 2017, registering 51 tackles, two sacks, and six passes defensed, and while the seventh-year pro is expected to start out in the middle, he has experience at both the strong- and weak-side positions and has the speed to factor in as an effective situational blitzer. That not only adds some flexibility and crucial injury insurance at every linebacker spot, but could free up the über-athletic Collins to rush the passer more often in certain situations. Oh, and the Browns’ young defense should get plenty of leadership from that position group, too—both Kendricks and Collins have Super Bowl rings.

An earlier version of this piece misidentified Dean Pees as Tennessee’s offensive coordinator; he is the defensive coordinator.