NFL: Former Super Bowl champion Jesse Williams spills on Jarryd Hayne

Rugby league player Jarryd Hayne. Photo / Jason Oxenham

When Parramatta Eels star Jarryd Hayne announced his move to the US to pursue his lifelong dream at making a career in American football, Australia went mad.

The media exploded, NFL merchandise sales skyrocketed and Google searches for "what is a running back?" went through the roof.

Predictions of Hayne's career-to-be spread around the NFL like wildfire after the bombastic young Aussie snapped up a spot at the San Francisco 49ers as an undrafted free agent.

The die was cast, he was going to be Australia's next big thing in the USA.

Despite displaying serious promise with a huge 53-yard run with just his second touch of the ball in a 49ers preseason match, the Eels star just couldn't impress the league enough to be a regular on the San Francisco unit's 53-man roster.

Fresh details of Hayne's stint in the US have emerged with former Super Bowl champion Jesse Williams uncovering how other Aussies in the NFL felt of the hype around the NRL star's code switch.

"It was an interesting situation, I was currently in the US when it all happened," the Aussie star told Fox Sports' League Life. "I've never met the person in my life ... but it wasn't well received by the other Australians in the NFL. (They were unhappy) with the story that was coming along with it. He was portrayed like he was the only Australian over there when there were already five or six (in the NFL) doing quite well.

"I think the way everything was handled wasn't the best and I think the magnitude of how the NFL is run and what it takes to play there is not seen by a lot of people.

"From being a representative of your team to having to learn plays. I played three years in the NFL and every day I had to work, learn and had to be on the ball every day. There was an iPad and it was updated almost every hour — if you didn't know (the new plays) when you went out on the field, you're useless. If it's not in your locker, you're cut."

Williams, who was diagnosed with papillary Type 2 cancer and was forced to quit playing football for the Seattle Seahawks in 2015, said the NFL is a "cutthroat" industry unlike anything experienced in Australia.

The 27-year-old agreed it was ignorant to think athletic ability alone would be enough to just walk into NFL and make a career.

"It's not guaranteed (you'll make it) unless you're signed," he said. "Without the notoriety or sort of using the media to get in, it would be very tough to, athletically, bounce through there. "I try to tell people who want to go over from Australia to the US — even I went over it was leading the way somewhat, there was a few people before me who were the next wave — there's so much in between that gets lost.

"I could go to WalMart in the US and find people who played three years in high school, and ran track who just made some wrong decisions (and didn't make it to the NFL). It's just such a hyper-competitive culture. If you make one slip-up, it's done."

Hayne announced his retirement from the NFL in 2016 before returning the the NRL, signing a contract with the Gold Coast Titans. The star back then gave up the lucrative deal worth $1.2m to return to his hometown Eels for the 2018 season.