Parramatta Eels full-back Jarryd Hayne is leaving Australia's National Rugby League to pursue a career in America's National Football League.
Hayne, 26, is one of rugby league's highest-paid players and was voted the best player in the NRL this year.
"I believe right now the time is right. It's the hardest decision I've ever had to make in my life," he said.
Hayne added his move is a 12-month project and he will rejoin Parramatta if an NFL deal does not materialise.
|Jarryd Hayne joined Parramatta Eels in 2006 and has since played 176 matches, scoring 103 tries and contributing 419 points. He has also represented Australia 12 times, scoring 11 tries.|
No Australian top-flight rugby league player has ever made the switch.
"For the past 24 months I've been thinking about having a crack in the NFL," said Hayne, who heads to the United States as a free agent. "In the past 12 months, I've been seriously considering it.
"I didn't feel like (my career) was challenging me to the point where I'll now be challenged.
"The easiest transition would be a punt returner or kick returner. This isn't going to be an easy transition and I'm aware of that."
Hayne has pulled out of the national side for the Four Nations tournament with England, New Zealand and Samoa, which starts on 25 October.
He is not the first rugby player to head to the NFL with Australian-born American second row Hayden Smith swapping rugby union at Saracens for the New York Jets in 2012 before returning to the Premiership club a year later.
American Miles Craigwell came the other way, having been in the practice squad for the NFL's Miami Dolphins before switching to rugby sevens in 2010.