ENGLEWOOD, Colo. -- The list of expectations for Denver Broncos quarterback Russell Wilson is plenty long. Start with, say, lifting a franchise back into the playoff conversation after six consecutive postseason misses.

But even Wilson can't do work in zone or man coverage and the most glaring remaining roster hole the Broncos have is in the secondary.

As general manager George Paton has said, "You can never have enough corners," and at the moment, the Broncos don't have enough corners.

The Broncos have made some of the biggest splashes during the NFL's offseason with the historical trade to acquire Wilson as well as signing outside linebacker Randy Gregory. They've bolstered other positions with potential starters in defensive tackle D.J. Jones, cornerback K'Waun Williams, linebacker Josey Jewell and offensive linemen Tom Compton and Billy Turner.

But Williams' signing won't, and can't, be the last in a secondary anchored by Pro Bowl safety Justin Simmons, who hasn't missed a game during the last four seasons. Four defensive backs who started at least one game last season are still unrestricted free agents -- cornerbacks Bryce Callahan, Kyle Fuller and Nate Hairston as well as safety Kareem Jackson.

Paton has said the Broncos have spoken with the representatives for Jackson and Callahan in an attempt to bring one or both back, but that Gregory's acquisition was the first move on defense.

"It's a passing league, offenses are dynamic," Paton said. "You have to be able to respond to that."

The Broncos spent much of the free agent negotiating period trying to secure Gregory and quickly signed Jones when the Broncos initially believed Gregory was going to stay with the Dallas Cowboys.

Williams, who has spent much of his career as a nickel cornerback, does fill a significant need for the Broncos given Callahan played much of last season in that role. Williams is more physical in run defense than most cornerbacks and has 11 forced fumbles to go with three 50-tackle seasons in his career.

"It's just a niche position that I've been able to play for a long time in this league," Williams said. "I have experience. I'm ready to lead and bounce some ideas off all the DBs in the room and elevate our whole defensive side of the ball -- to be able to attack the ball and play physical. That's going to be our standard on the defensive side of the ball."

So the Williams addition is a good one, but the Broncos' projected starting cornerbacks -- Pat Surtain II and Ronald Darby -- both missed time due to injuries last season.

Paton has said he does not want the team to "take a step back on defense" as it tries to repair its annually sluggish offense. Even with injuries to several starters last season, including linebackers Bradley Chubb, Jewell and Alexander Johnson to go with the trade of Von Miller just after Halloween, the Broncos still rose to as high as No. 4 in total defense and No. 1 in scoring defense in December.

Defensive coordinator Ejiro Evero has said he wants to crank up the pressure on opposing quarterbacks and pump up the turnovers -- "the ball is everything," he said. The Broncos haven't finished above 21st in the league over the last three seasons in takeaways and have finished above 17th in sacks in one of those three years.

"Getting the ball is everything," Williams said as well. "Providing the offense with more opportunities to make drives, that's what we do on defense. You just want the takeaway [by] any way possible, whether that's a forced fumble, TFL or just making a big sack. You just have to be there and make plays for your defense and being able to sacrifice for the team and make plays when your number is called."

But none of that is really going to work if the Broncos don't add some help in coverage. They are still combing the list of veteran cornerbacks available -- most of those are 30 or older -- and even after the trade for Wilson they have eight picks in April's draft.

"[We] feel good about those picks -- a second and two thirds, so we feel good about that," Paton said. "[We have] two fourths in the top 10 [of the round]. We're going to keep addressing our team. ... We still have some cap room to do some things, and we have a lot draft capital as well."