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Because of varying circumstances, there are some NFL superstars in line for a change of address next year.

Our first such player is different than the rest, being the only one with years left on his contract heading into the 2016 season. The rest are free agents, and it will be interesting to see how their respective teams handle the franchise tag when the time comes for such measures.

The following eight NFL stars, who are key players for their current teams, could be playing for different franchises next year.

Calvin Johnson, WR, Detroit Lions

It’s hard to say if Johnson’s skills have diminished or if it’s the rapport between himself and quarterback Matthew Stafford that is the problem. But there is no doubt the once-dynamic duo has lost some of their magic.

Courtesy of USA Today ImagesAfter a frustrating campaign last year in which Johnson dealt with some nagging injuries, he is once again playing at a level that is far below what one expects from one who has been dubbed “Megatron.” He is posting a career-low 13.7 yards per catch with just three touchdowns.

On top of all that, Detroit has turned into the biggest dumpster fire in the NFL and will likely be blowing up the roster a bit to rebuild in the coming years. ESPN’s Chris Mortensen speculated that Johnson could be on his way out, writing “Johnson seems more likely to be on the chopping block” than Stafford, citing his age (31 next year) and injury issues.

Pairing Johnson — who can still go up and get the ball as well as any receiver in the league — with a quarterback on a contending team, like Tom Brady and the New England Patriots, could potentially spark his aging bones to produce at the highest level once again.

Mohammad Wilkerson, DL, New York Jets

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Will the Jets want to keep Wilkerson? Oh, yeah. Big time. But can the Jets keep Wilkerson? That’s another question entirely.

Of all the free agents coming out in 2016, he’ll be the most expensive — by far. Ndamukong Suh signed a six-year deal with Miami this past year worth $114 million, with $60 million guaranteed. Wilkerson could match or exceed this next March when free agency kicks off, barring an in-house deal with the Jets, which seems improbable.

New York drafted Leonard Williams No. 6 overall this past spring and have Sheldon Richardson in the fold as well. While Richardson could be viewed as a risk, provided he stays out of trouble off the field he’s among the best defensive linemen in the NFL. Keeping all three players would be darn-near impossible for general manager Mike Maccagnan, who has other concerns to address.

Matt Forte, RB, Chicago Bears

This could be another Frank Gore situation for Forte and the Bears.

While Forte sits out with an MCL injury, young Jeremy Langford out of Michigan State has been going bonkers, and he’s a player the Bears can feature in the next few years — with many of the same multi-purpose skills that made Forte special — at a fraction of the cost.

Courtesy of USA Today SportsForte is going to want to feel respected in what will likely be his final chance at a decent-sized contract. He’s going to be 30 years old by the time the 2016 season starts, and as we all know the running back position is the easiest to fill via the draft, therefore the most expendable. Chicago could easily decide continue trimming the fat during this rebuilding process and let Forte test free agency, just like Gore did.

Another team on the cusp of winning a championship could decide Forte is worth $4-5 million per year with a nice $6-8 million up-front signing bonus. Chances are, Forte is going to find more money on the open market than he will from Chicago.

Josh Norman, CB, Carolina Panthers

General manager Dave Gettleman couldn’t have seen this coming. No doubt he and the Panthers coaching staff wanted to see Norman emerge as a league superstar, but they didn’t financially plan for it and have only $16 million in cap space for the 2016 season. If they had, then they would have signed him to a long-term deal before he blossomed into the league’s top cover man.

Norman is going to command top dollar for his services this March when he hits free agency. We’re likely talking at least $14 million per year (the franchise tag figure, should the team go that route), which would leave Gettleman high and dry to fill the needs of the team’s offense, which are plenty.

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While it would certainly be painful to let Norman hit the market, rather than use the franchise tag, Carolina’s defense is loaded with stars and could potentially compensate for his loss. On the other hand, as good as Cam Newton has been without much help on offense, he’s going to be even better if he gets some protection up front.

Overall, it seems like fixing the offensive line and perhaps adding another playmaker is of more importance than retaining one defender who may or may not be a one-year wonder.

Von Miller, LB, Denver Broncos

The 2016 Denver Broncos could look a whole lot different than this year’s crew. Quarterback Peyton Manning could be on his farewell tour this season, and the Broncos have many veterans that could be gone at the end of the year. John Elway truly went all-in to create the best one-year opportunity fro Denver to win a championship, which includes his recent trade to acquire tight end Vernon Davis.

Courtesy of USA Today ImagesMiller will be in line to receive a deal that is similar to the one Kansas City Chiefs outside linebacker Justin Houston signed at the deadline this summer. For reference, the Chiefs gave Houston a six-year deal worth $101 million, with $52.5 million guaranteed.

Elway has a huge rebuilding job ahead of him. The offensive line is a wreck and there are other key defenders, like Malik Jackson, who are in line to get paid as well.

It’s quite conceivable that the Broncos could end up losing Miller to free agency or suffer through a potential hold-out situation if he gets slapped with the franchise tag. He’s going to want top dollar after putting together an outstanding resume the past few years.

Alex Boone, OL, San Francisco 49ers

Even before the season from hell began for the 49ers, Boone had a contentious relationship with team management about his contract situation. He eventually settled on a two-year deal with the team before the 2014 season began. The way things have gone in San Francisco this year, though, nobody should expect Boone to be very interested in re-upping with the franchise for the 2016 season and beyond.

Could he perhaps jump ship and swim to the other side of the bay, a la Michael Crabtree, who is also due to be paid?

A diverse and skilled offensive lineman, Boone can play all over the line. Many 49ers fans and beat writers have wondered aloud why in the world the 49ers haven’t used Boone outside at tackle this year while Erik Pears stinks up the joint. Given his ability to play outside or in, he’s going to be a valuable free agent this March and should receive plenty of interest around the league.

Sean Smith, CB, Kansas City Chiefs

With the emergence of rookie Marcus Peters, Smith may be the odd man out this upcoming spring in Kansas City.

At the age of 28, he’s still in the prime of his career and is playing well enough to earn a substantial payday at the end of this season as a free agent. Unfortunately for the Chiefs, there are other free agents to consider, such as inside linebacker Derrick Johnson, outside linebacker Tamba Hali and safety Eric Berry.

Smith, at 6-foot-3 and 218 pounds, has the prototypical size teams are looking for these days, which is why the Chiefs were so eager to land him three years ago when he left the Miami Dolphins in free agency. He is physical, fast and has learned to play with sound technique. Smith is going to go where the money is, having never landed a mega-deal. Compared to Norman, he’ll be a bargain, though, and could be had for potentially $7-8 million per year.

Eric Weddle, S, San Diego Chargers

The tricky thing about having Weddle featured on this list is that one wonders if he’s a star any more, considering how bad the Chargers are on defense. San Diego’s secondary has been exposed on more than a couple occasions this year and isn’t creating turnovers very often. But Weddle hasn’t been the problem, allowing just one touchdown this year. He’s still a top player in this league.

Eric Weddle ChargersOne of the best safeties in the NFL — year in and year out — for more than half a decade, Weddle is disgruntled with the Chargers for their refusal to offer him a long-term deal that meets with his expectations of his worth.

“I feel highly, highly disrespected,” Weddle said about his decision to skip offseason workouts, per Kevin Acee of the San Diego Union-Tribune. “… It is what it is, but there is no reason for me to put out any more effort.”

He signed a record deal with the team back in 2011 that paid him $40 million over five years and will earn $10.1 million for his work in 2015. That’s quite a bit of money, but as the All-Pro safety comes up into his 30s he’s looking for one more big deal that will set him up for life, and general manager Tom Telesco wasn’t playing ball this past summer.