Jarryd Hayne's trainer: Biggest sports story in past 100 years

Jarryd Hayne playing for the San Francisco 49ers. Photo / Getty

If you had thought the Jarryd Hayne hype train couldn't get any faster, his former trainer has pushed his foot down on the accelerator.

Hayne's former trainer Hayden Knowles has said to Fox Sports News that in 10 years time, Hayne's successful code switch "will be the biggest story in the past 100 years of sport."

Knowles, who starting training Hayne when the now San Francisco 49er was just 16, declared "America hasn't seen anything yet", saying how the sky is the limit for the former Parramatta Eels star.

"America hasn't seen anything yet. Physically he was able to do this a long time ago, but emotionally and where he's at in his life now, he's so ready," Knowles said to Fox Sports News.

"Resource-wise, he's got it all. Physically, he's got the athleticism, and the most important resource is his drive and his want and his desire, but also he's being surrounded by people over there who have embraced that dream and taken him under his wing.

"In 10 years' time, this will be the biggest story in the past 100 years of sport.

"I really believe he will go to the top. He will become the very best."

Hayne was yesterday confirmed on the 49ers 53-man roster, but is at this stage predicted to be largely a punt returner, only getting minimal snaps at the running back position due to the status of impressive youngster Carlos Hyde and veteran Reggie Bush.

However, Knowles says Hayne's belief will push him all the way to the top, saying that his success is more than just a sports story.

"It's hard to put in words how powerful his belief is.

"I was privileged to travel with him on his first trip after he made the announcement and to tell you how powerful that belief was and how much evidence he gave me of how much he wanted it, we would be here all day.

"His life's always been about people saying he can't do something, so he proves them wrong. It's been about chasing dreams from day one for him."

Knowles, who now works with the Sydney Roosters, has a worrying tip for New Zealand Warriors fans - believing that Roger Tuivasa-Sheck is the next player who could make waves in the NFL.

"The next Jarryd Hayne is Roger Tuivasa-Sheck. If I was the NFL ... I would go and throw all the money in the world at him."