"I was a bit jittery at the start. I had to calm the nerves down and once I got on there it was a really good buzz, just like I always dreamed."
Perham played both codes throughout school – alongside and against his good mate Nanai-Seturo - and last year captained the Rotorua Boy's High first XV and represented the Kiwis Under 18s, having previously been signed on a junior contract with the Penrith Panthers when he was just 16.
He admits he has goals he wants to achieve in both sports, and the lure of the All Blacks jersey may prove too strong down the line, but he is currently contracted to the Warriors through to the end of 2020.
"Obviously there's goals there, but right now I'm just focussing on putting my best effort into the club and bringing what I can each and every day to training and on game day," he said.
"This is my first real proper season in league for the last three seasons, coming straight from schoolboy rugby.
"So I'm still learning the game and getting the gist of everything so I just want to settle in hopefully in the Under 20s and then build myself up from there.
"Right now I'm just focussing on what's best for the Warriors."
The club is understandably desperate to hang on to him, with speculation continuing to swirl around the future of off-contract Warriors captain and Kiwis test No1 Roger Tuivasa-Sheck, who has been linked with a cross-code switch while several other NRL clubs are also keen on his services.
"With kids like Hayze we've got to be visionary about the future," said Warriors CEO Cameron George.
"And that's what the whole sitting down and strategizing about what the next four years looks like for us.
"So with players like Hayze, it's their opportunity now to show us they want to be here long-term.
"And we've got to be smart – it's not who you sign, but who you don't sign and let go, to create space in the cap for kids like him coming through and others.
"But the club is very aware - and the recent situation with Etene obviously highlighted that - of the competition we have not only from New Zealand rugby, but the other 15 clubs that come looking."
Read more: Why the Warriors won the Etene Nanai-Seturo fight
Warriors coach Stephen Kearney said Perham had proved he deserved a taste of the big time after impressing at training over the pre-season, and denied his selection had anything to do with trying to convince to remain with the Warriors.
"I don't do that because I'm thinking that he's going to go to another code.
"If he hadn't have put in the work then I wouldn't have picked him. It's not based on because I want to sweeten him up to stay with us.
"He's a good kid. He's got some talent but he's an 18-year-old. He's done everything we asked of him and probably a little bit more. So I'm excited for what he can do but he's a baby."
Many have questioned whether either code should be signing youngsters to long-term deals, after Nanai-Seturo decided to switch to rugby in the middle of a five-year Warriors contract he signed when he was 15.
"It's all about the support – luckily for me my parents were with me every step of the way so nothing went wrong," said Perham.
"If I could give a tip to the families - just support your son in whatever he wants to do and whatever you think is right for him."
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