Oh if that was discovered to be the case the owners would have their team taken off of them and be forever banned from the sport kind of like they did with Pete Rose in baseball.
Rigging an entire football team would be impossible without someone talking. These players are not the smartest people, they wouldn't be able to keep something like that a secret.
I suppose the only way they would be able to pull it off would be if only the owners, the head coach, and the QB were in on it. Even then though, it would be really tough to pull off undetected. Plus all the team owners are billionaires and likely aren't interested in gambling like that.