Five biggest NFL offseason storylines

— -- SAN FRANCISCO -- As the final days of the 2015 season wind down, it's almost time to shift the spotlight toward the offseason. Here are the storylines that will dominate the weeks ahead, including the potential departure of a few of the league's longtime stars.

1. Fall of the legends

Broncos quarterback Peyton Manning could well be playing the final game of his iconic NFL career Sunday in Super Bowl 50, while Lions wide receiver Calvin Johnson, Seahawks running back Marshawn Lynch and Packers linebacker Julius Peppers may already have played theirs. Justin Tuck announced his retirement. During their careers, all of those players were as good as any at their positions.

Manning now gets his chance for the Super Bowl storybook ending that John Elway, Michael Strahan, Jerome Bettis and Ray Lewis once experienced, the ultimate capper to an all-time career. Manning might be the biggest name to leave the league, but he won't be the only one. Chances are Johnson retires, something the Lions have known was coming for a while, and that he reinforced to coach Jim Caldwell the day after the regular season ended. When Detroit interviewed coaches in 2014, they were told then of the concerns doctors had for Johnson's longevity and the condition of his ankles, so it will be no surprise if he walks away now.

As for the other notable players, Seahawks general manager John Schneider already has said it is his understanding that Lynch is "leaning towards retirement." Peppers is a nine-time Pro Bowl selection who made it sound like he has played his last game. And this list doesn't even include all-time great defensive back Charles Woodson, who announced this would be his last season before the Raiders' final home game. So this could shape up as quite an offseason for goodbyes -- and quite a potential Hall of Fame Class of 2021.

2. Remember the Titans

For having so many weakness on its roster, Tennessee sure is operating from a position of strength. The Titans have the No. 1 pick and their quarterback of the future, setting them up to draft any player they want or to auction off the pick to the team most desperate for a quarterback. If Tennessee remains at No. 1, NFL personnel executives said this week that there was a real chance the Titans would take Ole Miss offensive tackle Laremy Tunsil. That would give them bookend tackles with Taylor Lewan to protect Marcus Mariota and to run the ball for years to come.

But if Tennessee wants, it could trade the No. 1 overall pick to Cleveland (No. 2), San Diego (No. 3), Dallas (No. 4), San Francisco (No. 7) or any team looking to leapfrog the others to draft a quarterback. Cleveland has been in this position before, trying to go up one spot to secure the player it wants. Back in the 2012 draft, Cleveland traded multiple picks to Minnesota to move up one spot, from No. 4 to No. 3, to secure the draft rights to Alabama running back Trent Richardson. The Browns were worried that the Buccaneers wanted Richardson at No. 5. But former Tampa Bay general manager Mark Dominik confirmed Richardson never was an option, and so the Browns gave away picks for nothing. This time, they might have to trade picks to Tennessee to beat other teams to their QB of choice.

3. Let's make a deal

This year's free-agent class doesn't include an  Ndamukong Suh, a franchise-type player who is permitted to reach the open market without being tagged. On paper, a good group of players is set to become unrestricted free agents, but some will be tagged and others signed to long-term deals before their contracts expire.

Tampa Bay and Doug Martin are likely to figure out a deal that works for both sides, which would take one of the top running backs off the market before he gets there. Washington and quarterback Kirk Cousins are going to attempt to do the same. The Broncos are expected to use their franchise tag on Von Miller, with the Jets doing the same with Muhammad Wilkerson. Miami could possibly use its tag on pass-rusher  Olivier Vernon. But it should be noted that any good player who reaches the market is going to cash in. This offseason, more teams are expected to have more cap room than ever before. So the players who play it right could score big.

4. Revisiting 2012

Just as Andrew Luck and Robert Griffin III were the headliners of the 2012 draft class, they will be in the headlines again this offseason, albeit for entirely different reasons. At some point, the Colts are likely to sign Luck to a deal that will bind him to Indianapolis and ensure that generations of future Lucks are taken care of for life. When this deal gets done, it is projected to be for five or six years, at an average of between $23 million and $25 million, with somewhere in the vicinity of $65 million to $70 million guaranteed. Indianapolis has put off signing Luck; it can't put it off any longer.

Griffin will not be signing a deal like that with Washington -- or any team for that matter. It simply will be notable to see where he signs period, money be damned. Maybe Hue Jackson believes he can help revive Griffin's career, and wouldn't that be ironic, given that Cleveland got outbid by Washington to move up to No. 2 to draft the former Heisman winner in 2012. Maybe Chip Kelly will be the one who tries to revive Griffin in San Francisco. While Luck will be landing a blockbuster deal, Griffin will simply be looking for a landing spot.

5. Quarterback questions

It never seems to fail: When it comes to quality quarterbacks and the need for them, demand always exceeds supply. It will be no different this year. There are six teams in the definitely-need-a-quarterback department: Cleveland, Houston, Los Angeles, Philadelphia, San Francisco and Denver, where  Peyton Manning could retire and  Brock Osweiler is scheduled to become a free agent. There are a handful of others that will be in the browse-but-might-not-buy department: Arizona, Buffalo, Chicago, Dallas, New Orleans, New York Jets, San Diego and Washington. Others could be added to the mix as well, but almost half the teams in the league could be looking hard at quarterback.

The lack of solutions, as usual, is glaring. Cousins, Osweiler and  Ryan Fitzpatrick are scheduled to become free agents, though each could re-sign with his current team before he ever gets to market. Griffin, Sam Bradford, Colin Kaepernick and  Johnny Manziel are other players who could be available. No one knows which quarterback will wind up where this offseason, but we do know this: Not every team will solve its biggest need, and there will be more teams -- most likely in the top 10 of the 2017 draft -- still attempting to solve the issue that drags down franchises and gets men fired.

Other looming questions

What will the opening-night matchup be?

The Super Bowl winner gets the Vince Lombardi Trophy and -- with less fanfare now but more in September -- the NFL's Thursday night regular-season opener.

Denver's 2016 home schedule has more attractive options than Carolina's, but the NFL will find an appealing Thursday night matchup no matter who wins Super Bowl 50.

If the Panthers win Sunday, their most likely regular-season opener would be an NFC Championship Game rematch against the Arizona Cardinals, who are scheduled to play in Carolina next season. The NFL also could consider scheduling the Minnesota Vikings or Kansas City Chiefs, but neither of those matchups would hold the appeal that the Cardinals would. Arizona probably wouldn't be thrilled about opening in Carolina, not after what happened in the NFC title game, but it would be the most logical matchup.

If the Broncos take home the Lombardi trophy, the NFL would have three compelling options: a Super Bowl rematch with Carolina, an AFC Championship Game rematch with New England, or it could go off the board and schedule the Colts and Andrew Luck.

The guess here is that the league would not open the 2016 season with the same matchup that ended the 2015 season, so Carolina would be out. New England is always a prime-time draw, but because of the number of games it has played at night, it might leave the Colts as the most likely opening-night opponent for Denver.

So for now, the guesses are: Arizona at Carolina (if Panthers win Sunday), and Indianapolis at Denver (if Broncos win).

Which players will Denver and Carolina pay?

For all the benefits of making it to and winning a Super Bowl, there is a downside: the cost of doing business in the future.

Dallas learned it back in the day, after it won its Super Bowls. Seattle learned it in recent seasons, after its recent playoff runs. But the further a team goes in the postseason, the more players want to get paid at the appropriate time.

No team in the league faces more pressing contractual situations than the Broncos. Their list of unrestricted free agents includes linebackers Von Miller and Danny Trevathan, defensive ends Malik Jackson and Antonio Smith, safeties David Bruton Jr. and Omar Bolden, quarterback Brock Osweiler, running back Ronnie Hillman, wide receivers Jordan Norwood and Andre Caldwell, and offensive linemen Ryan Harris, Evan Mathis and Tyler Polumbus. Their restricted free agents include running back C.J. Anderson and linebacker Brandon Marshall. Not everyone can get paid.

Denver already has re-signed defensive lineman Derek Wolfe to a big deal, perhaps at the expense of Jackson. The Broncos have only one franchise tag, destined to go to Miller. The remaining players who don't sign long-term deals before the new league year starts in March would be free to solicit offers from other teams. A Super Bowl victory will be just what Denver wanted, but also costly.

Carolina has contractual issues of its own, though not quite as many as Denver. The Panthers' list of unrestricted free agents includes cornerback Josh Norman, who would get the franchise tag if no long-term deal can be worked out in advance, as well as wide receiver Jerricho Cotchery, safety Roman Harper, guard Amini Silatolu, cornerback Charles Tillman and fullback Mike Tolbert. No way the Panthers are going to let Norman go anywhere.

This is the cost of doing business in the NFL -- and a price any franchise will gladly pay in exchange for a Super Bowl title.