Actually that photo illustrates the biggest hurdle to a rugby player succeeding in the NFL: ball security. In rugby it's not that big a deal, because play doesn't stop when the ball hits the ground or is grabbed by the other team. Possession can change hands three or four times during a session of play, usually without the kind of catastrophic consequences we see in American football. Okoye will have to learn to hold the ball a lot tighter to his body than he has a rugby ball or, indeed, a discus. But the man is a beast.