The deck is stacked!
Unfortunately, NFL football is not a "plug and play" sport. You can't just randomly dump players in and expect them to play at their full capability with the rest of the team if they are unfamiliar with eachother. Payton Manning has gone on record several times to say that he feels all the OTAs and training camps and preseason games are a crucial part of building a team up, and that he wouldn't be able to play on a high level without it. So when you just toss a QB into the flames, 9 times out of 10 its a mess. Lightning strikes once in a while, but most likely it won't happen this Sunday! And I actually believe Quinn is a better QB than Cassel!
It's the same thing that happened to Croyle a few years back! It's just a move to make Pioli and Cassel look better. Let the backup that everyone wants to see play, but only give them half a week to practice instead of a whole training camp and year of preparation. Then, when the QB struggles, you can smugly bench him and start Cassel for another year!
There have been some threads claiming that the Cassel injury has been exaggerated, and I believe them! It's just a ploy to cover Pioli's butt again!