The end of the Peyton Manning era.

The Denver Broncos and their fans caught a glimpse of it last year. NFL analysts have been debating it for several seasons.

Manning struggled through a limiting thigh injury over the final five games (including playoffs) of last season before returning for what is very likely to be his final professional go around this year. Finally, it appears, that age has caught up with the 39-year-old QB. So what are the Broncos to do in a post-Manning life? That all depends on what backup Brock Osweiler shows them.

Osweiler, a 2012 second-rounder, has attempted all of 30 passes in his three NFL seasons. Such is the life of a Manning backup.

"Obviously, everybody in this league wants to play," he said via Nicki Jhabvala of the Denver Post. "Everybody in this league wants to be a starter. Everybody wants to be able to show what they can do. I came into a situation where if I had wanted to rush to the front of the line, you'd call me crazy."

But Osweiler's contract expires at the end of this season, meaning the Broncos will have to quickly decide if he is their future or not. John Elway had previously said that the young passer will be evaluated throughout training camp and the preseason. That means the real test will begin Friday when the Broncos play the Seattle Seahawks in their first preseason game.

With just 121 regular season snaps over the past three years, how will Osweiler ever be prepared for such an examination?

"I've watched Peyton in games," he said. "I've watched Peyton in practice. I've studied his tape - Why did he make this decision? Why did he do this? - so when I'm out there on the field I'm able to take some of those things and don't have to go through those experiences to necessarily learn them."

Osweiler is surprisingly mobile for someone who is 6-foot-7, but Denver quarterbacks coach Greg Knapp says he must improve his footwork to play better under center.

"The footwork tied in with the progressions, I'm seeing a very good improvement," Knapp said.

For his part, Manning has not been shy about playing the mentor and offering advice.

"Peyton has helped a lot with the mental things - what reads, what coverages you might see presnap, postsnap and to give him game examples of why he has read certain plays certain ways," Knapp said.

The hope is that all of this exposure will help Osweiler take the next step in Manning's absence. Whether or not he's ready to actually do it remains to be seen.