What nobody counted on at the time was the speed with which Indianapolis' revival would come.
As awe-inspiring as Manning's recovery and subsequent return to greatness has been, the Colts have penned their own remarkable turnaround story.
Some 21 months after finishing 2-14 with a season-ending loss at Jacksonville — and 18 months after choosing Stanford's precocious Andrew Luck with the No. 1 overall draft pick to become Manning's successor — Indianapolis is back in first place in the AFC South.
When Irsay drafted Luck, he repeatedly reminded the media it took the Colts six years to win their first playoff game with Manning under center. The obvious point was that it takes time to build a contender in the NFL.
Luck, however, has accelerated the process.
On Sunday, he and his teammates will get the opportunity to measure their progress against the best quarterback ever to play the game on football's grandest regular-season stage.
So, yes, it's still OK to root for Peyton Manning.
Just don't forget about the home team along the way.