World Rugby has also confirmed the former Eels superstar will not be barred from Rio contention by drug testing rules.

Hayne told reporters in London on Monday he had “a big mountain to climb” but would work hard for a place under Fiji coach Ben Ryan, and a spot in this weekend’s international comp in the British capital.

Hayne’s surprise announcement that he was leaving the San Francisco 49ers to seek a Rio berth with Fiji has sparked speculation about the 28-year-old’s return to the NRL, or a shift to non-sevens rugby.

He said he had made his decision to leave the NFL on Friday after receiving his Fijian passport.

His allegiance was to both Australia and Fiji the 28-year-old told reporters.

When asked if he had considered a return to the NRL and which team he might join, Hayne repeated the phrase “just taking baby steps at the moment”.

Hayne has not played sevens rugby before but said he had been in touch with friends for advice about making the transition.

“The biggest thing will be a lot more running that’s something I’m looking forward to.”

Hayne said he hadn’t thought about what he would do if he didn’t make the cut for the Olympics with sevens champions Fiji.

He said there was no drug testing impediment that would stop him playing in Rio, saying World Rugby had given him the go-ahead despite him not being on the drug testing register for the past year.

In a statement on Monday, World Rugby confirmed that, saying its rules do not require a player to be included in a testing pool for a defined period of time before being selected for international competition for the first time.

“Hayne would be eligible for the London round of the HSBC World Rugby Sevens Series subject to all other regulatory and registration matters being met,” the statement said.

“He would also be immediately included in World Rugby’s pre-Rio 2016 risk-based testing program.”

When asked why Fiji was keen to take on a star player like Hayne when the side were already champions, coach Ben Ryan told reporters “if you are good, you want to get better”.

Ryan cut the press conference short, accusing media of being rude to a security guard who interrupted the interview to order journalists to move only two metres back.

Meanwhile, the battle for Jarryd Hayne’s post-Olympic future is well and truly on, according to dual-code international Craig Wing.

While Hayne channels all his focus on Olympic glory, speculation continues to abound back in Australia on where the former NRL star will take his talents once the Games are over at the end of August.

Hayne’s old club Parramatta have previously claimed working out a lifetime deal with the mercurial superstar when he initially left the club for San Francisco in 2014.

He has also been heavily linked with the Sydney Roosters, while cashed-up rugby clubs in France and Japan could also be throwing open the chequebook.

“I’m looking forward to the bidding war that comes out of this,” Wing said.

One franchise that won’t be competing for Hayne’s signature is the ARU, who were ruled out the moment Hayne decided to represent the Fiji Bati in Rio due to stringent eligibility rules.

Wing hopes Hayne won’t be lured by big money overseas.

“He’s such a big superstar over here so I’d like to see him stay here, whether it’s rugby league or rugby union or whatever he chooses,” he said.

“He’s got so many people following him, and so many people got on board for his adventure to the NFL. I’m sure I’m like everyone else in that I just want to see him play.

“And for that to happen, he needs to be here.”

His manager Wayne Beavis, who ruled out his client from playing rugby union for Fiji as a long-term option, said Hayne had previously never been motivated solely by cash.

“He’s gone from the NRL on a lucrative contract to go over and play in the NFL on a three-year rookie contract, which let me assure you wasn’t on a lot of money,” Beavis told 2SM radio.

“And then he’s left that to go and play for someone who’s just going to pay for his accommodation and travel. It’s all the challenge for Jarryd than anything else. Money’s not a massive motivator for him.”

Wing, who played 256 games in 12 years in the NRL before switching to union, believes Hayne could be a more potent weapon as a league or union player once he improves his cardio.

“He’d need to work on his cardio a little bit,” he said.

“I don’t know too much about the NFL, but from what I’ve seen, after every effort you have, you’ve got quite a lot of recovery time. You just don’t get that in sevens, or rugby league even,” he said.

“But his speed and explosive power is probably better now than what we know and have seen of him in Australia. Add a bit of cardio to that and I’m really looking forward to seeing him one on one with a guy.”

-AAP