When i referred to him as a backup QB, I didn’t mean in terms of the league, Cassell would certainly start in many other cities. I meant he is the Pats backup QB and therefore his value to the Pats, is less than his value would be to the Chiefs, or some other time. Similar to people talking about the Yankees dealing from an area of strength (young pitching arms) for an area of weakness (CF).
When I saw they franchised him, my initial reaction was that there was no way they’d have two QB’s making that much money at the same time. So yes, I agree, Cassell was not utterly useless to them, but his value to them (considering he was their back-up), was to trade him for something they can use.