5 key storylines to watch during Super Bowl 50

The wait is almost over.

Super Bowl 50 kicks off Sunday, with Peyton Manning and the Denver Broncos taking on Cam Newton and the Carolina Panthers.

Here's what you need to know:

Newton unstoppable?

The NFL's soon-to-be MVP will face his toughest matchup yet in going head-to-head with the top-ranked Broncos defense.

Denver is fresh off a dominant AFC title game performance against Tom Brady and the New England Patriots, but Cam Newton is now far and away the NFL's most difficult player to defend.

As talented as the Broncos' defense may be across the board, it appears entirely possible that there simply isn't an answer for Newton's ability as a dual-threat quarterback.

He's elevated the play of an otherwise underwhelming supporting cast throughout the 2015 season, and that should only continue in his first appearance on football's biggest stage.

Capping off the incredible season with a Lombardi Trophy and a Super Bowl MVP award would be the final steps in making Newton's 2015 campaign one of the best in NFL history.

One last ride for Manning

Peyton Manning's expected retirement has been the talk of the league since the Broncos earned their spot in the Super Bowl. Win or lose, the future Hall of Famer is widely expected to call it a career after an incredible 18 seasons.

Though he's clearly no longer the player he once was, would anyone be all that surprised if he's got one last magical performance left in the tank?

There's little disputing that his physical skill set is in the midst of a rapid decline. Manning can no longer push the ball downfield, and that's limited the ways in which he can attack opposing defenses.

But the unmatched mental processing hasn't gone anywhere. With his ability to decipher defensive coverages pre-snap, getting the offense into the best play more often than not, Denver's best chance to win certainly still comes with No. 18 under center.

For a legendary player whose playoff shortcomings have earned him an unfair amount of criticism, going out with a second Super Bowl ring would be quite the finish to his illustrious pro career.

The Panthers' Linebackers

The key to Carolina's continued success on the defensive side of the ball is the superstar linebacker duo of Luke Kuechly and Thomas Davis.

Each are among the NFL's most well-rounded players at the position, with their consistent production in pass coverage representing the most important factor in potentially knocking off the Broncos.

This group, more than any other across the league, is best equipped to exploit Manning's limitations as a passer. Their presence underneath has the potential to both force him out of his comfort zone and force some game-changing turnovers.

Kuechly, 24, likely has a long career ahead of him, but Davis is an 11th-year veteran who's fought through an incredible amount of injuries to get to his first career Super Bowl.

Having overcome three ACL tears to re-emerge as one of the league's top defensive players, a broken arm suffered in the NFC Championship Game wasn't about to keep him on the sidelines.

The Broncos' defensive front

The Broncos' chances of limiting Newton's effectiveness start with the contributions of a star-studded defensive front.

Von Miller and DeMarcus Ware will certainly be relied upon to get in the backfield as pass-rushers, but their responsibilities will change with a quarterback of Newton's talent's under center.

Maintaining their respective pass-rush lanes, and particularly so on the edge, becomes imperative in taking away the potential for him to escape the pocket and either extend a play or take off as a runner.

As much as Newton's now developed as a pure pocket passer, the Broncos would much rather force him to test a strong defensive backfield than allow him to make plays with his legs.

Field-position battle

With a pair of strong defenses making it quite possible that this game ends up the lowest-scoring Super Bowl in recent memory, winning the field-position battle will be a focus from the outset.

Assuming that each team is thus given ample opportunities to field punts and make plays in the return game, perhaps the advantage in this respect goes to Carolina.

Tedd Ginn, a journeyman former first-round pick, has finally found a home with the Panthers. Not only is he making plays as a deep threat on the offensive side, but his athletic abilities are also being put to use as a return man.

Ginn finished the regular season ranked fifth among NFL punt returners with an impressive average of 10.3 yards per return. His 32-yard return in the NFC title game was mere inches away from going back for a touchdown, further demonstrating the explosive ability he has with the ball in his hands.