I was watching the US-Ned soccer match the other day. A Ned flopped and play continued. The Us drove down the pitch, failed to score. Ned retuen the ball over the middle field line where the US took the ball and moved back towrds teh Ned goal. During this whole time the Ned player who flopped, first layed on the pitch, then got up and hobbled towards midfield. When the US was making their second attempt to move in range of a shot on goal, the dude began sprinting. He almost caught the US player that had the ball. CLEARLY he had been faking. Clearly the refs ignored him.
It's unfortunate that NFL football can't let the teams play on when someone flops. The refs can't watch every single one of the 22 players at all times so it is rather difficult for them to know when someone is really injured or not. The only solution I can think of is to charge the team a timeout every single time there is an injury. That and post game review by the league can fine a player for faking an injury. Even that would be extremely subjective. And even if it is obvious, if the flop gives the defense a chance to regroup and they win the game, no one will care. An owner like Jerry Jones can stil find a way to get the player his money back. A Christmas gift for his wife or mother, A donation to the players favorite charity. Something.
Personally forcing a plyer sit sit out a game would be a real deterent but this soft league/society wouldn't stand for it. They would say the penalty is greater than the crime. If th NFLPA took it to court or arbitration, it would get overturned.