As we close down on the list, be sure to check out the previous rankings!

15. Stevan Ridley, RB New England Patriots

A starting quality back who may suffer from the Toby Gerhart misstep Jacksonville seemingly took when signing the former Viking and Stanford ballcarrier, Stevan Ridley is a thumper between the tackles. If teams are wary of signing a running back in free agency, especially with what seems to be the deepest draft class for runners in years, Ridley could come cheaper than he expects.

Again, Adrian Peterson's situation informs the strategy, but getting Ridley in to spell Peterson isn't a bad idea. Two-back sets with a combination of Peterson, Ridley and McKinnon on the field could be just as interesting an answer as the tight end craze seems to be against teams' continuing preference for nickel as their base defense.

Either way, Ridley represents a long-term investment while the Peterson investment at least looks like it's nearing its end. It may be difficult to convince a starting caliber back to wait a year or two while seeing perhaps 100 carries a year if he's lucky, but the alternative is him attempting to convince teams after coming off of an injury that he's a starting quality back and not just a rotational option or the product of Bill Belichick's genius—after all, LeGarrette Blount could only seemingly produce in New England, while Laurence Maroney petered out at his next stop and BenJarvus Green-Ellis was significantly less impressive in Cincinnati.

Ridley is a violent player whose intelligence isn't just put on display with his vision and patience, but his use of leverage to maximize power at the point of contact. Ridley forced 23 missed tackles in 2013 despite only 178 carries and had 2.2 yards after contact per attempt.

It's significant that New England, with their stable of running backs, had Ridley start all but one game for them this year before he went down. It helps that he happens to be one of the better pass blockers in the NFL, having allowed no sacks, two hits and three hurries in the last three years.

While he's not the fastest player in the NFL, he's a fair bit faster than most power backs, and that easily includes Matt Asiata. His acceleration stands out as a big point in his favor, even if he doesn't have the stop-start ability of a player like Percy Harvin or Darren Sproles. He's quick for his size and has decent breakaway speed (more than, say, Toby Gerhart) and is comfortable in the passing game, even though the Patriots preferred Shane Vereen in that role.

Ridley knows how to bait linebackers, both by pressing the hole as a runner and with relatively deceptive routes as a receiver and can find himself space that wasn't otherwise there. He's a consistent player (ranked seventh in Football Outsiders' success rate metric in 2013 and fourth the year before) that can grind out short-yardage plays; his career conversion rate on third or fourth down and three or less to go is 64 percent, while league average for running backs is 55 percent—and his rate rises to 68 percent if you exclude his rookie year.

The injury issue is of course worrisome. There's no need to project an Adrian Peterson or Jamal Charles-like recovery for him. Ridley was not only injured early in the year, but he may find himself in a situation (like with the Vikings) where he doesn't have to carry a significant load (or run at all) early in the season. His timetable isn't eight months, but 10.5 if he wants the first carry of the season, and over a year with the PUP list in effect.

Given his youth, he's a worthwhile investment. His team history and injury will depress his contract far below his likely value—he was already underrated in New England—and if the injury has a long-term impact on his speed, agility and power, he'll only be a rich man's Matt Asiata. Given the contract he'll command—probably no more than $1.5 million at best, that's almost a sure upgrade for very cheap.

14. Jabaal Sheard, DE Cleveland Browns

Like Jerry Hughes lower on the list, Jabaal Sheard comes with the value of flexibility. He played defensive end for his first two years in Cleveland and outside linebacker in the next two, and moved between two weights to do it. He played at 273 at defensive end and reportedly didn't shed too much weight to play outside linebacker, though it's likely he did regardless of how often the team said he didn't need to. His listed weight is 264, and that's also a reasonable guess for how much mass he actually carries.

Sheard put together his best year this year, despite only grabbing two sacks, largely because of his dominant ability to set the edge and control the run game. Despite only four tackles for loss, Sheard recorded the highest "run stop percentage" of 3-4 outside linebackers—making sure that running backs lost the down, even if they picked up a yard.

His pass rush on film looks better than it does on the stat sheet (7.5 sacks in two years admittedly looks quite bad), but Sheard, as a much more raw rusher in 2011 and 2012 earned 15.5 sacks over those two seasons, forcing five fumbles his rookie year.

While not extremely productive on the whole, Sheard seems a more natural fit at 4-3 defensive end than 3-4 linebacker despite improving as a holistic package in the 3-4. Those edge-setting skills can come in handy with the Vikings, and he won't be asked to play in coverage either, his biggest weakness (though the difference between 2013 and 2014 in that regard is stark).

As a pure pass-rusher, Sheard exhibits above-average strength and speed, though neither pop out, and he has good use of hands. Sheard displays exemplary field intelligence both as a rusher and run defender, but needs to clarify technique in finishing.

Given the scheme's emphasis on defensive ends playing contain first and foremost, Sheard could be maximized in Minnesota.

For a starter, Sheard would be disappointing, though likely better than Robison was last year. As a high-snap rotational player, Sheard would be the perfect fit, likely not commanding much in free agency but still providing high value as a subpackage player. Sheard has improved his coverage responsibilities enough to be a legitimate zone blitz coverage defender while still having the rushing and run defending chops to force the offense off schedule. He's not as good as other pass rushers on this list, but very few slot into a rotational role as well as he does from a price and scheme fit perspective.

13. Stefen Wisniewski, C Oakland Raiders

The Vikings don't need a center, that's not the point. Wisniewski at 313 pounds (occasionally listed at 307 or 315) is a perfectly acceptable size for a guard, and actually has guard experience with his time in Oakland, starting 13 games for them at left guard his rookie year, with a stint at center when Samson Satele went down.

The Raiders' original plan was to have Wisniewski play center—the position he was rated at coming out of the draft (he played both guard and center at Penn State)—but they liked Satele in camp enough to keep him at center and put Wisniewski on the field at guard. They didn't like Satele long enough to keep him there, and Wisniewski took over at center.

But he's underrated as a guard. He doesn't have the raw power as some of the NFL's strongest linemen, but some of the best guards in the league don't display dominating raw strength. Folks like Evan Mathis, Andy Levitre and Ben Grubbs have found themselves to play at the top level at their position despite average strength at their position. Like those players, Wisniewski wins with quickness, balance, footwork and leverage.

He can do that once more at the guard position, as he moves far better than people give him credit for, making him an ideal replacement for Charlie Johnson, who was the team's pulling guard on the majority of pulling plays.

A quick look at his Pro Football Focus grade (-2.5) may be disappointing, but it's a little misleading. He only had two games in the red (with a grade below -1.0) in 2014, and once in 2013 (where he finished with a total grade of +11.4). In 2012, he had a grade of +8.1, again with only one game in the red again. Over the last three years, his grade comes out to +17.0, with 12 games in the green (over +1.0) and four games in the red.

Further, his grade comes from a disappointing pass blocking grade (-5.6), where he still finished third of all centers in their Pass Blocking Efficiency rating, giving up only one sack, three hits and 12 hurries. All Pro centers Maurkice Pouncey and Travis Frederick had lower scores, with Pouncey giving up a sack, two hits and 16 hurries, while Frederick gave up a sack, two hits and 11 hurries—and Wisniewski had more pass blocking snaps than either of them (138 more than Frederick).

While this can be legitimately traced to the offense and Carr's quick release, there's a lot more talent at pass blocking than his grades imply, though less than those numbers. Oakland has left him one-on-one against defensive tackles often despite him being a center, and his only bad games in the last three years were against Terrance Knighton (who weighs more than 350 pounds), Barry Cofield (who weighs significantly more than his listed 306—laughing at the suggestion that he is at his listed weight), and 342-pound Paul Soliai.

Leaving any center alone against players who weigh 330-360 pounds is a recipe for disaster. Despite that, he handled Vince Wilfork, Justin Ellis and Ahytba Rubin with ease, all above 330 pounds. The point of these nose tackles is that they demand double-teams, and they surely would in most schemes, like the Vikings'—Sullivan almost always blocks them down onto a guard.

Further, the Raiders' pass protection schemes seem stultifyingly complex at times. Asked to block players shaded over the tackle at times, Wisniewski wasn't always put into a position to succeed. Despite that, he's been playing excellently, especially as a run blocker and he's been one of the best players in space and on the second level.

If Wisniewski can be tempted into playing guard, he'd be well worth the investment. Like Louis Vasquez was for the Broncos, he could be the young, hidden gem (he'll be 26 to start next season and is 25 now) that explodes onto the scene on the interior. Simplifying his duties and using his quick footwork as a pulling guard, his keen understanding of leverage and growing strength makes him not just an adequate replacement at guard, but a potentially top-level one.

Wisniewski may be hard to pry from the Raiders—he's one of the lucky few drafted to his favorite team, the team his uncle played for, and at the time, also the team that employed him. Uncle Steve was never fired either, resigning for personal reasons. His father wouldn't be too much help bringing to the Vikings either, as Leo played for the Colts.

On the other hand, he's turned down all offers from the Raiders thus far, saying it hasn't been what he's been looking for. The assumption has been that he'll receive a "solid" contract for a center, which would be probably under $5 million. He's probably worth over $6 million at either guard or center, and he can add strength, as he has every year for the past four.

12. Dez Bryant, WR Dallas Cowboys

This one isn't difficult. Dez Bryant is in the conversation to be the best receiver in the league, and he'll only be 26 years old to start the season. The Vikings, again, don't count receiver as a top acquisition need for them entering the offseason despite questions with Patterson and Johnson with regards to their development, but Bryant can only help the offense, and in non-redundant ways.

Bryant's major knock coming out of the 2013 season, if there were any significant ones, was his inconsistency, particularly when it came to concentration. He did have issues getting on the same page as Tony Romo, but that was resolved pretty quickly. His concentration drops have plummeted, and his drop rate of 5.4 percent is better than A.J. Green's, Alshon Jeffery's, Julio Jones', Brandon Marshall's, Calvin Johnson, Jordy Nelson's and DeMarius Thomas'.

The mercurial receiver is noted for his size and speed combination, as well as his enormous catch radius, but while that's all true, Bryant is a stellar route runner as well. He continues to have issues at times with option routes but he tells a story with his route running that allows him to deceive even high-level defensive backs and work his way open. Even if he won't win with deception, he'll win with fluidity and explosion.

The Vikings need a receiver to win contested balls. Dez Bryant is arguably the best in the league at it. It's not just 50-50 jump balls he wins—though he wins his fair share of those—but catches in traffic, on slant routes, against in-breaking safeties, over a defender, in the middle, and so on. He knows how to use his body and size and has always had a natural understanding of leverage and positioning. It's not just that he's a deep threat, but he's a threat anywhere on the field, and he's the rare player—like Calvin Johnson and Rob Gronkowski—who is open when he's blanketed in coverage.

Add to that his complete familiarity with the Coryell and Turner systems, and Bryant is a natural fit. It might be awkward for the Vikings to find a way to get all their receivers on the field, but it's well worth that struggle to sign Bryant, as expensive as he may be.

Further, here seems to be an argument that Bryant may not command the salaries that Fitzgerald and Johnson commanded—his off-field concerns early in his career aside, his usage pattern doesn't match them, and though he's unique like they were when they signed. Given that he'll be competing with Demaryius Thomas for a team, his salary could be depressed by ready market supply (though don't expect too much).

If Bryant can be had for under $15 million a year—which is a somewhat absurd possibility given some of his performances—he should be targeted.

11. Joe Barksdale, OT St. Louis Rams

Barksdale has gone under-the-radar for the last two years as a viable and even "good" offensive tackle. The St. Louis Rams probably want to keep him, but have the flexibility to move on from him with tackle-capable players in Jake Long, Greg Robinson and Rodger Saffold.

The interesting thing about Barksdale is that his high level of play has not been met with commensurate plaudits or predictions of a good contract in this free agency. Barksdale earns barely a mention even as one of three players highlighted in the St. Louis Post Dispatch's piece regarding Rams free agents and Fox Sports Midwest regards him as an incidental target to keep—because there's "not many reasons not to keep" him.

It seems like the perception of his limited ceiling makes him the kind of free agent teams sign "for the right price" but only made a priority because he's assumed to be cheap.

It's true that Barksdale had a shockingly poor season as a pass protector after playing extremely well in 2013, but it's also the case that neither Jake Long nor Greg Robinson did well at all from the tackle spot. Davin Joseph and Scott Wells also ranked near the bottom of the league in pass protection metrics. It may be the case that Austin Davis and Shaun Hill are not particularly adept at manipulating the pocket and avoiding pressure.

It so happens that the year before, Scott Wells was the best center in the NFL at preventing pressure, while Jake Long and Davin Joseph both outperformed their 2014 selves—with Long finishing well within the top half, unlike this year.

It seems unlikely that four members of the offensive line would suffer dramatic drops in pass blocking effectiveness at the same time (with some going worst to first) without an external factor at play, in this case the sack avoidance abilities of Kellen Clemens and Sam Bradford exceeding those of Austin Davis and Shaun Hill.

In 2013, the two quarterbacks combined to have an average pressure-to-sack conversion of 17.8 percent—less than a fifth of all pressures led to sacks. In 2013, Hill and Davis exceeded that, ranking as the eighth-worst.

It also isn't a surprise that Austin Davis had the fifth-highest number of snaps under pressure; he had the 4th-longest time to attempt in the NFL. When the Rams switched to Shaun Hill, both the rank of snaps under pressure (19th of 39) and time-to-attempt (30th of 39) fell dramatically.

Barksdale isn't a bad tackle, and there's a good likelihood that he's better than Kalil. Regardless, his struggles in Oakland and his recent run of play will depress his market despite the fact that he was a better than average tackle in 2013.

Further, he can play guard. His strengths are magnified there (leverage, power, punch, drive) and some of his weaknesses can be covered up (reading in space, quickness). At 326 pounds, he has the size for the position, and he certainly has the attitude. He can be a violent player and this year improved his run blocking from the tackle position quite a bit. His hand usage is frenetic but good, and he usually makes first contact against pass-rushers, something that can help him out at guard.

He wouldn't replace Charlie Johnson as neatly as Wisniewski would, but he can be had for cheaper and offers more versatility at positions of need.

It's a similar situation for some of the other offensive line signings on this list. Barksdale is a starting-quality player that can be had for replacement-level price (despite never being injured in his NFL career). The Vikings can start him at guard and let go of Charlie Johnson, while at the same time investing in an insurance policy in case Kalil's late-season improvement was just noise and not a genuine return to form.

While not as talented as some other offensive linemen on this list, his potential price is tantalizing enough to move him up the rankings.

Head over to Vikings Journal to take a look at some of the most interesting wagers you can make, figure out why the Pro Bowl is even played or see where the Minnesota Vikings landed in a draft re-grade.

Arif Hasan is a senior writer for Vikings Journal and the editor-in-chief of Vikings Territory. He is a former political consultant and a Minnesota native.