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The NFL is down to its final four teams, and all is quiet on the home front as the Minnesota Vikings catch their breath and analyze the season that just was and begin to play with the puzzle pieces that will make up the picture for next season and beyond.

The next step for every NFL team is to assess the free-agent market and figure out what players might help their team while being financially reasonable.

It's those last two words that many NFL fans tend to gloss over. A common refrain on comment threads across the league read something like, "If we can just sign Randall Cobb, Devin McCourty and Mike Iupati, we'll be set for next year!"

Dare to dream, but not only have you just blown right by the NFL's salary-cap number, you've probably financially crippled your team for the next five years.

No. NFL teams, including the Vikings, have to take a more measured approach. Not only do they have to analyze their salary-cap numbers for next season, but they have to look into the future and make guesses as to who on their current team will be looking for big raises and how that might impact your salary cap down the line.

We'll leave the future to the Vikings brass and their salary-cap expert, Rob Brzezinski. But how about this year's free-agency class? How much available money do the Vikings have to realistically spend on free agents?

Well, that all depends. Like every other NFL team, the Vikings have numerous player personnel decisions looming that will have a domino effect on every other move they make.

According to ESPN NFL Insider Adam Schefter, the NFL believes the 2015 salary cap will be between $138.6 and $141.8 million. Schefter also says that the NFLPA believes that as much as $10 million could be added to the cap based on increased league revenues.

Working off a $140 million salary cap, the Vikings would have roughly $10 million in cap space heading into 2015, according to Over the Cap. That available number will obviously change as Minnesota begins tweaking its roster in the offseason.

With those numbers in mind, let's take a look at some Minnesota veterans who are likely candidates to have their contracts restructured or cut completely.

Player Position 2015 Cap Hit Cap Savings if Cut Before June 1 Cap Savings if Cut After June 1 Adrian Peterson RB $15,400,000 $13,000,000 $13,000,000 Greg Jennings WR $11,000,000 $6,000,000 $9,000,000 Chad Greenway LB $8,800,000 $7,100,000 $7,100,000 Captain Munnerlyn CB $3,833,333 $3,166,000 $3,500,000 Charlie Johnson G $2,500,000 $2,500,000 $2,500,000 Jerome Felton FB $2,500,000 $2,500,000 $2,500,000 Brian Robison DE $5.450,000 $2,450,000 $4,450,000

All numbers are courtesy of OvertheCap.com.

Obviously the biggest and most important name on that list is running back Adrian Peterson. Football-wise, you want him back. Of course you do; he makes the Vikings a much more formidable team.

Financially, however, it makes no sense at all to bring him back under the terms of his current contract. Peterson is due to make $12,750,000 next season, with a cap hit of almost $3 million more than that. No running back is worth that kind of money—not even close.

If the Vikings truly want Peterson back, they'll offer to renegotiate his deal. If Peterson isn't willing to do that, Minnesota can cut him and free up $13,000,000 in cap space.

Wide receiver Greg Jennings is another option for the chopping block. If Minnesota decides to cut Jennings, it won't be until after June 1, as his "dead money" figure would drop from $6 to $2 million, and their cap savings would rise from $6 to $9 million.

Jennings obviously still has value as a receiver, but he's being paid like a No. 1 guy, and he's not that anymore. It will be interesting to see if the Vikings go after any big-name free agents at wide receiver, and if they do, it would be a pretty good indication that they're planning to cut Jennings after June 1.

Alex Brandon/Associated Press

As for linebacker Chad Greenway, it seems like both sides would like him to be back with the Vikings, but he'll probably have to take a pay cut or the Vikings will release him, according to Master Tesfatsion of the Star Tribune.

According to Chris Tomasson of the Pioneer Press, cornerback Captain Munnerlyn fully admits to underachieving in 2014 and knows that he might get cut. He's an interesting case because, while creating $3 million in cap space is attractive, Minnesota is thin at his position, and cutting starters isn't the best way to improve.

The Vikings could parlay that money into looking for another free-agent corner along the lines of Byron Maxwell, Perrish Cox or Chris Culliver.

Lynne Sladky/Associated Press

Defensive end Brian Robison was very disappointing in 2014. He finished 15th on the team in tackles with just 24 on the season, two behind rarely used linebacker Audie Cole. His 4.5 sacks were a big drop-off from his last three seasons, and he's going to be 32 years old come April.

The Vikings could save $4.45 million against the cap if they cut him after June 1. Rookie third-round draft pick Scott Crichton was kept under wraps for most of the year, and we have no idea if he's ready to take on a meaningful role next year. As a third-round pick with a year of practice under his belt, he should be.

If not, the Vikings might be a player in free agency at defensive end.

Fullback Jerome Felton, knowing the Vikings would not pay him $2.5 million in 2015, will opt out of his contract and become a free agent, according to Tomasson. Felton's role on the team shrunk dramatically under Norv Turner, and Minnesota will be more than happy moving forward with the much cheaper Zach Line at fullback.

Left guard Charlie Johnson remains a good candidate for the chopping block, but we've been saying that for three years, and he keeps popping back up in the starting lineup. We'll say it again, though; Johnson will be cut, and Minnesota will pick up $2.5 million in cap room.

Of the above table, Felton and Johnson are the best bets to be gone. That's $5 million more in cap money.

As for the rest of the list, nothing either way would be a huge surprise. If Peterson and Greenway aren't willing to restructure their deals, they'll be cut. That would provide $20 million in cap space, but it's more likely that they try to bring them both back at reduced rates.

It's fruitless to even guess at what might happen with Peterson yet. After his tumultuous non-season in 2014, he may be looking for a fresh start somewhere else. The only near-certainty is that no team is going to pay him anywhere near the $15 million he's due next season.

As for the current roster, one has to think the Vikings will be looking to lock up safety Harrison Smith to a long-term deal as he heads into the final year of his rookie contract.

As it stands, the Vikings are about $10 million under the cap, and that number could go up depending on how high the cap is raised depending on league revenue, as per the earlier link to Adam Schefter.

The Vikings should be able to pick up at least $15 to $20 million more in space by renegotiating with, or cutting, the players listed above.

Whatever the number ends up being that the Vikings are under the cap, they should be in pretty good financial shape when free agency opens on March 10.

Where they spend that money is completely up for grabs. Offensive line, wide receiver, defensive line, linebacker and secondary are all in play.