Even the staunchest Peyton Manning supporters must concede that he is finally looking his age. The 39-year-old quarterback has gutted out two ugly victories to start the season but appears less physically capable on the field than ever before. Manning is completing just 58.8 percent of his passes while throwing for a career-low 5.07 yards-per-attempt. That's not to say he can't turn it around. But it's looking more and more like this may be the last season for Manning.

So where does that leave the Broncos? Outside of the offensive line, this is a top-notch roster that can compete in the AFC. If they can make a smooth transition under center post-Manning, they should still be in playoff contention. But how will that transition go down?

Denver currently has 2012 second-rounder Brock Osweiler entering the final year of his contract while third-stringer Trevor Siemian is a rookie seventh-rounder.

"As we sit here today, I expect them to make a strong effort to keep Brock Osweiler," Troy Renck of the Denver Post wrote. "He made strides in the spring and preseason. Any real evaluation will have to wait until a real game, but his progress was encouraging. There's no denying how highly this coaching staff thinks of Trevor Siemian. I do think it would impact their search for a quarterback if Osweiler were to leave via free agency. They would still look to add depth, but I doubt they would use a high draft pick for the position."

Osweiler, all 6-foot-8 and 240 pounds of him, has thrown just 30 career passes. Although John Elway used training camp and preseason to evaluate him, nothing of matter can be gleamed until he's put into live game action, as Renck said.

Still, there's a reason why Elway liked Osweiler back in 2012 and it would be surprising if he let him get away in free agency. Expect Osweiler to receive the first crack at replacing Manning whenever that time comes.