Perhaps it's a wishful Vikings writer's thought, but Mark Craig of the Star-Tribune believes Manning and Caldwell are a buy-one, get-one deal:
If Peyton Manning is staying with the Colts next season, there is no way in the world he's going to let Indianapolis change head coaches. So Jim Caldwell is safe ... unless Manning isn't.
who ever wrote the above satement is stupid, to think that Manning has that kind of authority. He still wouldn't do that if he could
When you want (and/or desperately need) your HoF QB to re-negotiate his deal to give you time and flexibility, you'd be surprised at what kind of authority you're willing to give him in order to get him to drop a tiny bit of the massive leverage that he has.
That said, I don't believe Manning's as attached to Caldwell as people seem to think.