In 2015, the Denver Broncos defense had the unique ability to rush opposing quarterbacks in waves and from multiple positions along their front seven. With Derek Wolfe and Malik Jackson up front and Von Miller and DeMarcus Ware coming off the outside, it was a two-pronged attack along the defensive front seven and a matchup problem for offensive coordinators around the league.

What didn’t get noticed, is the players behind those starters that helped to elevate the defense to a different level. In Antonio Smith and Vance Walker on the defensive line and then-rookie Shane Ray and Shaq Barrett providing breathers for Miller and Ware on the outside, Denver had a depth to their defense that is rare in today’s NFL. With the endless assault of so many talented pass-rushers getting after the quarterback, Denver racked up a league-best 52 sacks for the 2015 season.

Free-agency and retirement have not been kind to Denver in the years since, and while the team still boasts Miller, Wolfe and Ray amongst its ranks, the Broncos no longer can bank on having a surplus of defenders to bring down opposing signal-callers. Gone are key pieces from that championship-winning defense like Ware and Jackson along with depth players like Walker and Smith. The Broncos began the process of shoring up the substitutes when they brought in Jared Crick in free-agency last season and drafted Adam Gotsis in the second round. They continued to fortify the ranks this offseason, selecting DeMarcus Walker in the draft and signing Zach Kerr in free agency. The front office believes that quartet can get Denver back to the same level of interior productivity they enjoyed en route to a Super Bowl 50 victory.

Things are far more questionable at outside linebacker, as an offseason injury to Barrett will see a thinned-out linebacker group behind Ray and Miller. In Denver’s 3-4 defense under new defensive coordinator, Joe Woods, Ray and Miller figure to be counted on heavily to supply most of the edge rush for this upcoming season. Miller is a top-5 player in the NFL and Ray took a giant leap forward in his development last season, subbing in for an injured Ware. Having multiple pass-rushers in Ware and Barrett kept Miller and Ray fresh, with little drop-off in performance. However, the team no longer can claim the same number of skilled outside linebackers at this time.

2016 was a testament to how the depth was affected when Ware first went down with an injury. It was a luxury to have Ray waiting in the wings to replace him, but it also meant that Barrett was less effective. As the only player seeing substantial time subbing for Ray and Miller, his sack and tackle totals fell from 2015 to 2016. For as much as Vontarrius Dora and the now-departed Dekoda Watson tore up the preseason, they had little impact once the year started, leaving Miller to log more time on the field without the respites he was afforded in 2015.

With Barret’s injury, Dora figures to see his reps increased with the hope he can continue to trend upward. The signing of former New Orleans Saint Kasim Edebali, on paper, looks like a similar move to find another Watson-type linebacker who can provide some pass-rush help as well as chip in on special teams. After that, all the team has left on the roster are undrafted rookie free agents in Deon Hollins from UCLA and Ken Ekanem from Virginia Tech. Unless a personal move is made before the start of training camp, the team looks to stand pat on its group of linebackers.

Not every team can have a surplus of good players in multiple years; free-agency and the salary cap sees that rosters face noticeable turnover each season. Denver is now in the middle of that familiar NFL cycle of replacing and developing players to plug holes along its roster.