Ranking Detroit Lions' Best Remaining Free-Agency Options

Free agency isn't how you build a team. It's how you fill in the gaps between your draft classes or find that one piece needed to push your franchise over the edge.

That's why the Detroit Lions haven't gone crazy. Despite fans' dismay, general manager Martin Mayhew has identified the players who can plug the holes in his roster at a reasonable price and won't break the salary cap. He already has a handful of homegrown guys to do that.

For the most part, he's done a solid job. Detroit has at least one starting defensive tackle and a solid rotational interior defensive lineman with a lot of potential. He also retained the best kicker Detroit has had since Jason Hanson traded in the Lions' den for the living room.

There's just a few more positions to fill. The offensive line needs a left guard, and the defense needs an outside cornerback (or two) and another defensive tackle. Click through to find out the six best candidates to fill out the roster taking into account price and talent.

6. OT Jake Long

Evan Habeeb/Getty Images

It's tough to sell the notion of signing Jake Long. The injury history that matches his name and his age are two issues that some can't look past, as pointed out by ESPN's Dan Graziano:

"

Jake Long turns 30 in May, has torn ACL twice and hasn't played a full season since 2010. What's appealing there?

— Dan Graziano (@DanGrazianoESPN) March 9, 2015"

But there is opportunity in the above information. Those torn ACLs are going to lower his price considerably, probably resulting in a one- or two-year deal heavy on incentives and light on guarantees. And the Lions don't have to sign him sight unseen, as noted by NFL Philosophy:

"

Yes, I think Jake Long, if healthy and passes a physical, could be a great addition at either RT or LT.

— NFL Philosophy (@NFLosophy) March 10, 2015"

The Lions are not set at right tackle. The hole isn't the size of the crater left of center or at cornerback, but Long was a legitimate No. 1 pick who finished the 2013 season with the seventh-highest tackle grade, according to Pro Football Focus.

We've recently seen Adrian Peterson come within eight yards of setting the single-season rushing record after a nasty knee injury. Science has and continues to limit the long-term damage of injuries. Long's pain could be Detroit's gain since they created an opportunity to cheaply scoop up a top-tier talent.

5. DT Kenrick Ellis

Gail Burton/Associated Press

Tyrunn Walker's signing gives Detroit another piece for the interior defensive line. The Lions have always used a healthy rotation up front, and it could be premature to presume Walker's success in limited snaps will stretch to starter productivity (although it could).

Plus, Walker is a 3-technique who can't elongate Haloti Ngata's career. But former Jets nose tackle Kenrick Ellis can.

At 6'4" and 340 pounds, Ellis can anchor a line against the run, eating up blocks but also making plays, as Pro Football Focus' Nathan Jahnke illuminated recently:

"

Random free agent I think deserves a look: NT Kenrick Ellis. Led all NT/DT with a 14.9 Run Stop % in 2013

— Nathan Jahnke (@PFF_NateJahnke) March 12, 2015"

His on-field value is certain, and others have taken notice. Mike Garafolo of Fox Sports 1 tweeted that "[s]ix teams have been talking to him" as of March 9.

However, head coach Jim Caldwell highly values character, and Ellis was arrested after a college fight. But the story is somewhat murky. Rich Camini of ESPNNewYork.com wrote: "Ellis said he was defending his girlfriend, sources said." That's a far cry from the domestic-violence issues that currently plague the league. Since he hasn't been in trouble since, perhaps Caldwell will see it fit to give his young man a chance.

3. OG Justin Blalock

Bob Leverone/Associated Press

The link between Justin Blalock and the Lions isn't as speculative as the first two players were, as confirmed by DetroitLions.com reporter Tim Twentyman's comments :

"

Yes. Had a good visit from what I hear. Doing his due diligence, as he should. @nxcharles: @ttwentyman did blalock leave without signing?

— Tim Twentyman (@ttwentyman) March 13, 2015"

Obviously, that tweet from Twentyman indicates the Lions are are still in the chase for Blalock. Michael Rothstein of ESPN has the lowdown on the other interested parties:

"

I'm told Justin Blalock had a good visit with the #Lions, per a source. St. Louis and Tennessee are also interested.

— Michael Rothstein (@mikerothstein) March 13, 2015"

The market for serviceable guards is slim. It seems to consist of aging veterans or players better suited as backups, so the interest in Blalock isn't surprising.

His on-field performance isn't nearly as enticing as Ellis' or Long's, though. Blalock earned a 2.1 pass-protection grade from PFF, and he gave up just two less quarterback hurries than Rob Sims. Plus, his run-blocking checked in at negative-0.2, which is basically league average.

But his position is a much-bigger priority for the Lions today, and Blalock doesn't have Long's injury history. For those two reasons, he beats out the former two for fourth on this list.

3. CB Rashean Mathis

Duane Burleson/Associated Press

When things are going well, there's no need to shake things up. Rashean Mathis will be the test case for the old cliche (pun intended) "if it ain't broke, don't fix it."

Everything points to bringing Mathis back. He finished 2014 as the 12th highest-graded cornerback in the league. He's a well-documented mentor for a secondary that has a young cornerback on the rise, young talent in the slot and the possibility of a draftee.

And he came quite cheaply last season, leading to him picking up a nice bonus check for outperforming his meager contract, as noted by Josh Katzenstein of The Detroit News:

"

CB Rashean Mathis leads all Lions in performance-based bonus from 2014 with $227,241.98. RG Larry Warford second with $152,012.66.

— Josh Katzenstein (@jkatzenstein) March 13, 2015"

The other side of the coin, however, is worn around the edges, and the date is hard to read. Time is especially cruel to aging defensive backs and Mathis will be 35 next August.

Ndamukong Suh's departure means the team needs everyone to pick up their play to compensate for his loss. After watching Champ Bailey fall apart last year, Mathis has to take a backseat to the next two guys on this list.

2. CB Patrick Robinson

Rogelio Solis/Associated Press

If listing Long on this list made you question my competency, this Patrick Robinson pick will send you to the comment section faster than a Tim Tebow mention. (Don't worry. None are forthcoming.)

But hear me out. Robinson represents a chance to answer a big present-day and long-term question with one signing.

Robinson put together a middling effort in 2014 (40th overall, per Pro Football Focus), but he was the 19th-best cornerback in 2011 per that same grading scale. In between? There was a nasty injury involving his patella.

The key will be the compensation. After he lost most of 2013 to the above injury and was only so-so in 2014, it's possible that Detroit could grab a solid starter for cheap, but his market may be heating up as the options start to dwindle, as NFL Insider Ian Rapoport's tweet noted:

"

Former #Saints 1st round CB Patrick Robinson is taking his first visit to the #Steelers this weekend, source said. He has others interested

— Ian Rapoport (@RapSheet) March 14, 2015"

The severe need for a starting cornerback pushed Robinson up this list. His upside, youth (27) and cost-effectiveness gave him another boost. The only on-field concern is his physicality, but he was actually a more effective tackler than Mathis. While Robinson's tackling ratio (successful tackles to misses) was 5-1, Mathis' was only 4-1.

1. CB Tramon Williams

Tom Lynn/Associated Press

It's debatable whether Detroit's biggest need is cornerback or offensive guard. What isn't is how important both positions are, and that's why Tramon Williams tops this list.

The Green Bay vet is well-known in Detroit. He's held down one side of the Green Bay Packers defense for the past six years, his best season coming in 2010 when he earned a Pro Bowl invite and won the Super Bowl.

And, as Aaron Nagler of SI.com pointed out, he takes advantage of opportunities when they present themselves:

"

Tramon Williams' 22 interceptions since 2010, including playoffs, are second only to Richard Sherman among active players.

— Aaron Nagler (@AaronNagler) March 13, 2015"

Williams is three years younger than Mathis and is more consistent than Robinson. The upside is capped at this point, but Williams offers a dynamic that the other two don't. Williams either notched a hurry, hit or sack on 15 percent of his pass-rushing attempts, which is eighth among cornerbacks.

Detroit has to find someone to strengthen the secondary. Williams is a better bet than Robinson with a lesser fear of a dramatic decline than Mathis. If Martin Mayhew can land him, he needs to set the hook.

UPDATE: Everyone on this list just moved up a spot.

"

Former Packers CB Tramon Williams has reached a three-year agreement with the Cleveland Browns, per source.

— Adam Schefter (@AdamSchefter) March 16, 2015"

All salary-cap numbers are sourced from Over the Cap unless otherwise noted. All advanced stats, grades and positional rankings are sourced from Pro Football Focus.

Brandon Alisoglu is a Detroit Lions Featured Columnist who has written about the Lions on multiple sites. He also co-hosts a Lions-centric podcast, Lions Central Radio. Yell at him on Twitter about how wrong he is @BrandonAlisoglu.