Warbler said:

you know, it might be interesting to get some the NFL stars to play rugby against some of the other countries. We'd have to figure out which NFL players would best for the rugby team. We'd then have to give them some to learn the rules of the game and what not. With rugby being similar to football, I bet the NFL players would do well.

They've done that. Some Nfl player (think he was wide receiver) can't remember his name, came over and trained with the London Irish rugby team. He came on as a sub in a game aswell. He found it tough going. It was more the endurance side of the game and getting used to having no pads which he found tough. He left with a new found respect for the game.