In a word (or two): Oh. No.
And does this tell you everything you need to know about how deeply concerned about Peyton Manning the Colts really are?
I mean, good, lord, if you're willing to bring Brett Favre and his two pals, Barnum and Bailey, to town, Peyton's neck must be in truly bad shape. Because the dynamic of this would be absolutely horrible.
I can't imagine a man with Favre's immense ego being willing to hold anyone's coat, even if it's Peyton Manning's. And I can't imagine Peyton being comfortable having a spotlight-craving guy like Favre looming over his shoulder, waiting for him to go down so he can step in and (presumably) save the day.