Free agency is a fleeting whirlwind of landscape-changing roster movement. The top talents are typically off the board within the first few days of the offseason as teams look to secure coveted targets. 

Not all of them, though. 

A handful of quality performers, capable of starting, remain available. Granted, it's a small group with questions marks, but wise teams that decided to wait out the market will be able to revisit free agency and address problem areas that persist after the draft. 

Recently, an influx of talent from the now-defunct Alliance of American Football spurred free-agent interest as organizations added depth to their rosters.

A few recognizable names like Eric Berry and Marshawn Lynch remain available, but how much they can actually contribute at this point of their careers is in doubt. 

Meanwhile, a pair of high-profile defensive linemen remain unsigned and a Pro Bowl left tackle is available to help a squad in the twilight of his career. We'll discuss multiple key contributors, even if they're not full-time participants, who can be signed at a discount price and help squads.

RB Jay Ajayi

Injuries have been a part of Jay Ajayi's professional career before he entered the professional ranks and are now the reason why he's unsigned. 

Ajayi was one of the top running prospects in the 2015 draft class, but he fell to the fifth round because of concerns over how a 2011 ACL tear might compound the regular wear and tear at the running back position. 

"I just don't know if he'll hold up physically," a scout told the Milwaukee Journal Sentinel's Bob McGinn before the draft. 

Ajayi hasn't played a full 16-game slate in his first five seasons, culminating in another torn ACL last season against the Minnesota Vikings in Week 5 after experiencing knee soreness in 2017.

The running back's health concerns are obvious. Yet, he's an effective downhill runner when he's on the field and, unlike the 32-year-old Marshawn Lynch, he's still in his prime. The 25-year-old back rushed for 2,329 yards in 33 games since the start of the 2016 campaign. Essentially, he's put together a pair of 1,000-yard campaigns in two seasons of work. 

A team can find a home for Ajayi in its backfield rotation as long as the medical staff clears the talented runner. 

RB T.J. Yeldon

Some free agents take longer than others to drum up interest. T.J. Yeldon only recently made visits to the Buffalo Bills and New England Patriots. 

Both of those possibilities are interesting for the same reason. The Patriots already feature James White, Sony Michel and Rex Burkhead while the Buffalo Bills have veterans Frank Gore and LeSean McCoy splitting carries.

Yeldon looks to be a role player in a rotation. But he fits a very specific role as a third-down back. 

In four seasons, the 2015 second-round pick has pulled in 171 passes. He finished second in receptions on the Jaguars last season, behind Dede Westbrook's 66, with a career-high 55 grabs. 

As the game becomes more specialized, a back with Yeldon's skill set is a necessity even if he is not viewed as a starter. 

The latter point is a primary reason why he hasn't drawn much free-agent interest. The Jaguars drafted Yeldon to feature in their offense. He never developed into a lead back, though. As a result, the team drafted Leonard Fournette two years later. Other teams never had the same expectations. 

Yeldon is a 25-year-old back who, even in crowded backfields, can carve out a defined role.

OG Stefen Wisniewski

Stefen Wisniewski became a starter as a rookie and made 101 career starts through eight seasons. Yet, he's never found a permanent home. 

The 2011 second-round pick opened his career at left guard with the Oakland Raiders and center with the Jacksonville Jaguars before he signed with the Philadelphia Eagles. Wisniewski then returned to guard, but played all over the Eagles front in three seasons. His versatility and experience are definite positives. 

Even so, the Eagles declined Wisniewski's option this year after the organization moved Isaac Seumalo into the starting left guard spot. 

Whether the 30-year-old Wisniewski starts at his next stop or serves as a team's sixth lineman, his value isn't in question. At the very least, he provides quality depth at all three interior positions. 

The search for quality offensive linemen never stops. NFL coaches struggle to develop the position and those coming into the league aren't as prepared for the professional game as they once were since spread offenses don't concentrate on the fundamentals. Furthermore, 2011's restrictions on contact in practice continue to make it far more difficult to build continuity within the offensive line group.

Wisniewski can be relied upon and that alone makes him a valuable addition.

OT Donald Penn

Quality left tackles are few and far between. 

That's exactly why Nate Solder and Trent Brown became the NFL's highest-paid offensive linemen in successive years despite neither ever playing in a Pro Bowl or earning All-Pro honors. 

With three Pro Bowl appearances, the latest coming in 2017, Donald Penn was once considered one of the league's very best. But age and injuries took their toll after starting 170 straight contests. 

The blindside protector's '17 season came to a close when he required foot surgery. Penn rebounded and started the first four games of the '18 campaign at right tackle before he landed on injured reserve with a hurt groin. 

Penn turns 36 years old next week, which doesn't make him an ideal addition. However, when healthy, he can still play a premium position. He wouldn't even be the league's oldest left tackle as Jason Peters, who also had several injury setbacks, already turned 37 this year. Another starting tackle, Andrew Whitworth, turns 38 in December. 

Multiple franchises still have questions marks on the blind side. A few, like the Houston Texans, Jacksonville Jaguars and Arizona Cardinals, could benefit from adding Penn to their lineup. 

DT Ndamukong Suh

Ndamukong Suh has already made more than enough money to be patient for the right free-agent deal. 

A year ago, the five-time Pro Bowl defensive tackle waited 11 days before he signed a one-year, $14 million contract with the Los Angeles Rams. 

Available free agents are now a month removed from the start of the new league year, but Suh shouldn't be worried about the market since he has been specific about certain parameters. Most notably, he wants to stay on the West Coast. 

The options are therefore limited, even more so when franchises that can actually afford Suh are taken into account. 

The 32-year-old defensive tackle shouldn't expect the same number he garnered a year ago. But he isn't going to sign for chump change either. Only three West Coast teams have the current salary-cap space to absorb a Suh-level deal, a contract in upwards of $8-10 million: the San Francisco 49ers, Oakland Raiders and Arizona Cardinals. 

Two of the organizations mentioned—the 49ers and Raiders—are expected to select defensive linemen near the top of the draft's first round, though. 

Suh dominated during the Rams' Super Bowl run. He's extremely difficult to handle at the point of attack. While the three-time first-team All-Pro may not be the player he once was, he can still be a force in the middle for another franchise if he becomes more flexible with his priorities. 

DE Ziggy Ansah

Ziggy Ansah is biding his time before he signs with a new NFL franchise. 

According to NFL Network's Ian Rapoport, teams continue to wait for more information on Ansah's injured shoulder. A better read on his situation will come after the draft for two reasons: First, the defensive end had his four-month medical checkup in the middle of April. Second, with a draft class that's absolutely loaded at his position, teams won't be ready to invest a significant dollar amount until they've made their selections.

So, Ansah must wait. 

But he shouldn't have to wait too long since premium pass-rushers aren't readily available this late in the process. 

Yes, Ansah's injury history is worrisome. However, 29-year-old proven edge-rushers with a pair of 12-plus-sack campaigns are especially rare. Even if Ansah's physical ability to hold up is concerning, the rewards outweigh the risk. 

According to Pro Football Focus, the end amassed 271 quarterback pressures in 80 career appearances. Every team is continually searching for disruptive edges, and the former Lion fits the bill. Team interest will skyrocket once he's medically cleared. 

LB Jamie Collins

The Cleveland Browns made Jamie Collins the game's highest-paid off-the-ball linebacker after acquiring the defender in a 2016 trade from the New England Patriots. 

Collins is one of the league's most naturally gifted linebackers. But inconsistent performances and lack of effort continued to dog him, even though the 29-year-old led the Browns last season with 104 total tackles and 13 tackles for loss. 

Despite a productive campaign, the return Cleveland received wasn't on par with Collins' paydays. His impact didn't rival other top-paid linebackers like the Carolina Panthers' Luke Kuechly and Tampa Bay Buccaneers' Lavonte David, who each had at least 20 more solo tackles than Collins' 73.

As a result, the organization chose to release Collins and saved $9.25 million against this year's salary cap.

Obviously, he can still play at a high level and his versatility allows defensive coordinators to use him in a number of roles. He's a natural Sam 'backer in base packages with the ability to rush the passer or drop into space depending on the call. Very few second-level defenders run as well as Collins, and he has shown a propensity for big plays at points during his career. 

A much cheaper deal for an inspired Collins will make an organization look brilliant. 

LB Zach Brown

Linebacker Zach Brown turned into a tackling machine over the past three seasons. Brown secured a whopping 372 total tackles over the last three seasons (15 more than five-time first-team All-Pro Luke Kuechly). 

Brown put together a career year in 2018. According to Pro Football Focus, he finished as one of three off-the-ball linebackers, including Kuechly and the Seattle Seahawks' Bobby Wagner, to register run-defense, coverage and tackling grades above 80. 

Despite the outstanding effort, the Washington Redskins decided to release Brown at the start of the new league year. Brown knew the move was coming and still played outstanding football. 

"I mean, you see the writing on the wall," the 29-year-old said in December, per the Richmond Times-Dispatch's Michael Phillips. "It is what it is. I've just got to contribute to the team and help us make the playoffs.

"I think they're just going in a different direction towards everything. I'm going this direction, they're going that direction." 

Washington's loss can be another team's gain because Brown is one of the league's best middle linebackers against the run and a much-improved pass defender. 

CB Morris Claiborne

A team can never have too many cornerbacks, or the saying goes. Secondary depth is absolutely vital for any organization since five or more defensive backs are on the field for most snaps. 

Morris Claiborne couldn't stay healthy during his five-year Dallas Cowboys career after the organization spent the sixth overall pick in the 2012 draft on him. He then signed two successive one-year deals with the New York Jets and proved to be far more durable. After starting just 43 games in his first five seasons, Claiborne started 30 in the last two. 

Granted, Claiborne didn't develop into a shutdown corner with the Jets. He did play well in stretches, though. For example, he graded as an elite corner through the first quarter of the 2018 campaign, according to Pro Football Focus. His inconsistencies showed up later in the season with multiple poor performances. 

No team is going to sign Claiborne with expectations of him solving all of its coverage problems. At worst, the 29-year-old can come in, compete and become a defense's third or fourth corner. At best, he works his way into the starting lineup.

Either way, Claiborne's acquisition is worth consideration based on his experience at a premium position. 

S Tre Boston

Safety Tre Boston isn't happy with a lack of free-agent interest, nor should he be. 

"Stats are beyond there! OBVIOUSLY!" Boston tweeted in response to a Pro Football Focus stat about the safety allowing the lowest passer rating among NFC West defenders last season. "The players see it. The fans see it and are starting to question what's going on. I like it, keep asking questions." 

Last year, Boston signed a one-year, prove-it deal with the Arizona Cardinals after an outstanding season in coverage with the Los Angeles Chargers. 

Yet, teams don't seem to have much interest in the free safety despite an obvious skill set as a rangy backline defender with ball skills. The previous sentence could be construed as oxymoronic since sideline-to-sideline single-high safeties are currently in vogue. 

Furthermore, Boston is only 26 years old with strong-safety experience. He had to wait until July 25 to sign a deal last year; there's absolutely no reason, with his level of play the last two seasons, to be available that late in the process again. 

Boston's perplexing availability may be due, in part, to contract demands. Even so, a proven starting-caliber free safety is available for any team to sign and insert into its starting lineup.