How it might end for Peyton Manning

There is a possibility -- admittedly, as slim as a tassel waving from the top of a goalpost upright -- that Jan. 8, 2011, will go down as Peyton Manning's final appearance in an Indianapolis Colts uniform. And if that possibility becomes reality, it will have happened for one of two reasons:

• His latest neck surgery -- an anterior cervical fusion procedure Sept. 8 -- fails to correct a recurring nerve problem and he reluctantly retires from the NFL.

• The Colts cut him or trade him.

Manning doesn't deserve either option, but since when does the NFL care about happy endings? It is America's most violent team sport, played by men whose average career spans are measured in single digits, not decades. And unlike in the NBA or MLB, their contracts aren't guaranteed.

So it's silly for anyone to simply assume Manning will play again because his surgeon says he will, or because the Colts have kept him on the active roster. After all, don't you think Manning's doctors told him after the second procedure, the one performed this past May, that they were confident of his chances to return in time for Indy's season opener?

The Colts thought so, which is partly why owner Jim Irsay handed Manning the richest contract in league history: a five-year, $90 million deal that includes a $20 million signing bonus, $3.4 million in base salary and another $3 million when he was added to the 53-man roster.

By the way, that roster bonus kicked in only a few days before a doctor made an incision in the front of Manning's neck and began the fusion procedure.

Manning now has had only one fewer neck operation (three) than league MVP awards. He is 35 and his body has been subjected to 13 seasons of abuse. How he never missed a start from his first NFL day in 1998 through that Jan. 8, 2011, playoff loss to the New York Jets -- a string of 227 consecutive games -- is beyond me.

Now he is damaged goods, a guy whose medical chart in the past 19 months features lots of notations about neck disks. This isn't a torn ACL, where you fly down to Birmingham and Dr. James Andrews repairs the tear in his sleep. This is scarier stuff, with a wider range of recovery time.

If there is a consensus on Manning's latest procedure, it leans in the direction of non-career-threatening. But until he can throw a football with authority -- and do so as 1,200 pounds of defensive linemen are breathing down his surgically repaired neck -- then nobody, including No. 18 himself, knows how this is going to play out.

Colts management -- Irsay and team president Bill Polian, in particular -- are saying all the right things these days. They say Manning's health is their overriding concern, that there remains a chance he could return before season's end. They say that as long as he can play football -- either this year or if they have to wait until next year -- Manning will play it as a Colt.

That's nice. But circumstances change. This is mid-September. What happens if Manning's recovery lingers past December, through January and into February, when Irsay and Polian have to decide whether to exercise a $28 million option bonus on their soon-to-be 36-year-old quarterback? Then what?

They can pay the money, figuring Manning has another six months until the 2012 season begins. Or they can keep their $28 million and cut him outright, or try to trade him in time for the April draft.

All Manning has ever known is playing football. Well, that and making commercials. He didn't want to miss this season. He's a gamer. Always has been, always will.

But there's a weak spot in every business relationship, and in the end that's the essence of the NFL: It's a business. If the San Francisco 49ers could part ways with team icon Joe Montana at age 36, the Colts could do the same with Manning. All allegiances have their breaking points.

If Manning feels the tiniest bit weird about collecting $26.4 million this season without playing a down, he shouldn't. He tried to come back in time. He's still trying to come back. Plus, you never hear NFL teams apologize when they cut a player over money. (See: David Garrard and the Jacksonville Jaguars.)

Nobody would blame Manning if he walked away. Injuries forced quarterbacks Steve Young and Troy Aikman into premature retirement. If the same thing happens to Manning, his football legacy is carved in bronze. He'll be a first-ballot HOFer and join Young and Aikman in Canton.

Meanwhile, there is now a legitimate possibility that the Colts are going to stink it up this season, and stink it up spectacularly. And yes, I know it was only one game, and that quarterback Kerry Collins was making his first start after only a few weeks of prep time, and that the Colts were playing the division-favorite Houston Texans on the road. I also know that nobody can make fun of Collins as long as Minnesota Vikings QB Donovan McNabb keeps putting up seven-completion, 39-yard passing days.

Collins will get better, but will it matter enough to make a difference? Veteran middle linebacker Gary Brackett, who makes all the defensive calls for the Colts, is out for Sunday's game against Cleveland. So is reserve linebacker Ernie Sims. Last week, the Colts trailed Houston 34-0 at halftime with Brackett.

Five of the Colts' first eight games are on the road. After the Browns, they play Pittsburgh, travel to Tampa Bay, face Kansas City, go to Cincinnati, then New Orleans, then Tennessee. A 1-7 start isn't out of the question.

The second half isn't any gentler: Atlanta, Jacksonville, Carolina, at New England, at Baltimore, Tennessee, Houston and at Jacksonville.

Can you say "Andrew Luck"? (Don't read too much into it, but according to Sports Illustrated's Peter King, Polian was at last Saturday's Stanford-Duke game scouting Luck.)

It could happen. Anything could happen with the Colts during the next six months. They could recover. They could tank. They could welcome back Manning. They could place him on the curb.

Loyalty is an inch deep in the NFL. Here today, gone tomorrow. Just like Manning could be.

Gene Wojciechowski is the senior national columnist for ESPN.com. You can contact him at gene.wojciechowski@espn.com. Hear Gene's podcasts and ESPN Radio appearances by clicking here. And don't forget to follow him on Twitter @GenoEspn.