Every NFL fan is aware that Denver Broncos quarterback Peyton Manning is nearing the end of his Hall of Fame career. At 39-years-old, how could he not be? But what fans want to know right now is if they still have a shot at a Super Bowl with Manning under center and what will happen when the 18-year vet finally decides to hang it up.

Luckily, ESPN Broncos reporter Jeff Legwold sat down with ESPN Radio to answer some of these questions.

"If the phrase 'Manning at QB' is the key part, everyone knows it's year to year now," Legwold said. "Some people thought he couldn't raise his level of play to where it was last year when he threw for 4,727 yards and 39 touchdowns."

While Manning still had a phenomenal season statistically, it was clear that he was not the same QB down the stretch. Whether it was a nagging thigh injury just or plain old Father Time, Manning's passer rating over his final five contests (including playoffs) was just 79.9 and his TD-to-INT ratio was just 4:6. Those are far cries from his career averages of 97.5 and 530:234. Is Manning in decline and, if so, what does that mean for Denver moving forward?

"The window on Manning is closing. Around him, they have a fairly young team including five Pro Bowl guys on defense. The key question other than Manning is what happens with Von Miller who is a free agent next year. They have a young team but have to answer the QB question in a fairly short window."

Manning's backup is Brock Osweiler, a 2012 second-round pick who has attempted just 30 regular season passes in three seasons. General manager John Elway realizes that he'll have to start planning for a post-Manning future, which is why the Broncos are trying to figure out what they have in Osweiler this offseason.

None of this means Manning won't turn in another fine season this year. But the clock is ticking extra quickly.