JARRYD Hayne is building towards “something special”, with his Australian-based coaches reporting striking physical and mental gains ahead of his second season in the NFL.

Hayne returned to the US this week and will link-up with the San Francisco 49ers for pre-season training next week — his first chance to work with new head coach Chip Kelly.

The former NRL star recently spent three months in Australia but it was anything but a holiday. He continued working throughout, holding sessions with strength coach Cato Rutherford and long-time trainer Hayden Knowles.

Both worked with Hayne when he was first pursuing what seemed an impossible dream last year and have been able to witness the incredible strides he’s made in the last 12 months.

Hayne’s coaches spoke to foxsports.com.au about the 28-year-old’s progress and what it could mean for his 2016/17 NFL season prospects.

DETROIT, MI - DECEMBER 27: Jarryd Hayne #38 of the San Francisco 49ers walks off the field after losing 17-32 to the Detroit Lions at Ford Field on December 27, 2015 in Detroit, Michigan. (Photo by Gregory Shamus/Getty Images) Source: Getty Images

INCREASED POWER

When Hayne began working with Rutherford at Lift Performance in Redfern last year, the initial focus was on improving his structural balance and range of movement to prepare for the physical rigours of the NFL.

Significant improvement in that area during his first season has allowed Hayne to now focus more on power and acceleration — areas critical to his position at running back.

“It was very obvious to myself and him also when we started working together (this time), he noticed straight away he felt better, stronger, felt more balanced,” Rutherford said.

“It felt as though his preparation second time around was a lot more complete and he was walking in knowing a lot better how his body was going to perform.

“His body was firing a lot better because he also worked on (balance) a lot with his coaches in the States.

Always a pleasures working @liftperformancecentre my man Cato keeping my body aligned 👌🏽 A photo posted by Jarryd Hayne (@jarrydhayne38) on Mar 22, 2016 at 4:52pm PDT

“One of the big stand out improvements with Jarryd was just his rate of force development, his explosive strength. That had really come a long way and that’s very important for someone that’s playing his position – the ability to go from zero to 100 in a short time period.”

Hayne’s recent power gains have been eye-catching, according to Knowles, who is also on the coaching staff with the NRL’s Sydney Roosters.

As part of their summer work, Knowles included Hayne in a field session with Andrew Johns and the legendary rugby league halfback was blown away.

“Andrew just turned to me and said, ‘Holy s**t, how powerful is he?” Knowles said.

“His (Hayne’s) genetic make-up is all about being powerful and now his training is very suited to that. In his rugby league days he had to spend a lot more time on the endurance of the game.

“I would say he’s much more powerful a year on.”

MENTALLY STRONGER

Knowles says Hayne’s physical gains, and much-improved understanding of American football, have also done wonders for his mind.

“Last year there was a real powerful belief he had that I used to try and explain to people,” Knowles said.

“But this year, it felt differently for me. When I was with him it felt like there this real powerful confidence.

Jarryd Hayne visiting his old primary school during his return to Australia. Source: News Corp Australia

“Last year, he was kind of doing the impossible, believing and having faith, but this year there was just so much confidence. I guess because he knows what he’s heading into and he knows what he has to do.”

Knowles said Hayne’s focus and commitment had also gone to another level.

“Most people, give them three months off, they’d go and have a break,” Knowles said.

“I’m sure he rested when he got back (to Australia) but … mainly is focus every day was all about training, which was pretty professional of him. He didn’t have anyone pushing him, it was all him.”

PREDICTIONS FOR SEASON TWO

Cato Rutherford: “I think we’ll see a lot better, more powerful, more explosive, more confident athlete on the field and I’m confident the improvements will be obvious not only to the viewers and the fans but also to his teammates and to the 49ers HQ.

“In terms of athlete development, Jarryd’s actually right where he needs to be with regards to his age and his choice of sports.”

Hayden Knowles: “I said a few outlandish things last year, that he was going to shock the world, and I don’t think anyone really believed me when I told them.

“This year, that confidence that he’s got, it could mean anything. I really believe he could take it to another level and the guys that have believed in him over there, I think they’re going to be repaid tenfold.

“He’s so educated on the game now, whereas last year he was going over to be that student. Now he’s ready to, I wouldn’t say dominate, but that’s that vibe I get from him. I get this vibe he’s going to do something really special.”

Hayne will need to be at his very best to earn a spot on the 49ers’ 53-man roster amid reports he’s slipped to the No.6 running back, according to the first unofficial depth chart of the team’s roster.