Peyton Manning has always been a split-second ahead – of the pass rush, of the opposing coordinator, even of his own receivers. Perhaps never in the history of the NFL has there been a quarterback as in tune with his surroundings as Manning was with the Indianapolis Colts. There was no static in the channel, no delayed reaction, no pause of uncertainty.

With the 2012 NFL draft in the rear-view and Manning's official comeback from neck surgery only a few months away, is it reasonable to think he'll be that same quarterback for his new team, the Denver Broncos? Time is catching up with the legend – not only Father Time, but also reaction time, which is crucial for any passer. Several factors are now eating away at that time advantage, and they may add up to more than the split-second that always seemed to keep Manning upright and victorious.

Rich Gannon, a onetime foe of Manning's, sheds some light on what the future Hall of Famer faces.

Gannon will be the first to tell you he was no Peyton, but at one point he was a quarterback in his late 30s … making a comeback from an injury … with several Pro Bowls under his belt … coming off a raft of double-digit-win seasons … working with a new offensive system on an AFC West team … dealing with high expectations for plenty of points and wins. Sound familiar?

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The ex-Raider great passed for 4,689 yards in 2002 and led Oakland to the Super Bowl before a shoulder injury and a long layoff in 2003. Then coach Norv Turner came in with a new plan in 2004, and after a long offseason, Gannon was ready to dominate again.

Didn't happen.

"By the time we played Week 1," Gannon says, "I wasn't prepared."

The Raiders went 2-1 under Gannon, but he felt a step slow. Then the quarterback sustained a serious neck injury and was forced to retire. The Raiders went 5-11.

Gannon isn't worried about the same thing happening to Manning, but he is concerned that what was once so automatic for the former Colts icon is not going to be seamless anymore. At least at first.

"He's coming from out of football for an entire year," Gannon says. "He's had to rehab his back, his neck, his arm. Now there's a new environment and a new system. That's a real challenge."

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