I'll tell you where it originated.
Before this season of NRL started, and around when the NFL was in the off-season/camp, the Parramatta Eels traveled to Seattle to study the Seahawks. How they prepare, how they run their org, coach, etc etc. The whole thing. Not sure if the whole team went, or a small contingent of players, or even if any players went, but there was a line of co-operation between the Seahawks and Eels. There must've been some interest shown by the Seahawks at the time....just like you're seeing the NFL (not just NCAA) starting to look around the world for athletes who might adopt the game. Menelik Watson is an example. So is Margus Hunt. Ezekial Ansah. Joplo Bartu. Among just a few. The Seahawks no doubt just offered him to come and try out. Not like he'll make it. But Hayne, a long-time NFL fan, is admirable here. It's always been a dream or a love, and he's 27, still young, and before he gets too old, he wants to give it a shot. As someone else said, he'll be back in 2015 for the Eels. 2015, not 2016.