Pats shouldn't overestimate Cassel

It's hard to imagine a situation in NFL history quite like the one Matt Cassel finds himself in as we enter the free-agency period. How many other quarterbacks with almost no career record had excellent seasons right before they hit free agency -- knowing their starting jobs were temporary because of a veteran returning from injury?

The Patriots placed the franchise tag on Cassel as soon as they were able, but nobody is sure of the reason yet. Did they need an insurance policy in case Tom Brady is not ready to return in September? Or did they figure that quality starting quarterbacks are so rare that they had to hold on to a bargaining chip that could get them an excellent return in trade? Until they make a decision, the Patriots will have nearly 25 percent of their salary cap tied up in quarterbacks, making it difficult for them to be active in free agency.

We know that Cassel took the wheel for one of the greatest offenses in NFL history and managed not to crash the car. Would he be just as good with another team? And what would the Patriots do without him?