Katoa (19) made a big impact for the Otago Boys' High School First XV last year, using his considerable size and strength at No8.
Before that, Katoa attended Waitaki Boys' High School, where he played in the front row in the First XV.
His agent, Amon Ta'akimoeaka, said Katoa had attended a South Sydney training camp in Auckland earlier this year.
''He made a good impression, just with his fitness levels and his sheer size. They wanted him to go across to Sydney and have a good look at him,'' Ta'akimoeaka said.
Katoa played in a couple of trial games while in Sydney, also playing in front of scouts from Wests Tigers and Manly.
But the Warriors were hovering and, given the opportunity to come back and play league for the New Zealand club, Katoa decided to head back to Auckland.
He signed a one-year contract with the Warriors, which would give him a small income. He was now training three days a week with the Warriors under-20 team.
Ta'akimoeaka said Katoa was still learning the game and had linked with Auckland club side Papakura. The club's senior side is coached by former Kiwi Richie Blackmore.
Ta'akimoeaka said Katoa needed to play games to know how to play the sport well. But he had physical attributes - nearly 2m tall, and about 110kg - that could make an impact in the code.
He was likely to play prop or second row in league, although he played in the centres for the trials.
Ta'akimoeaka said a chat with Brad Thorn was part of the reason Katoa decided to have a crack at the 13-man game.
''Brad talked to him and said to him he had the style of play which would be suited to league. He told him if he ever got the opportunity, then he should give it a chance.''
Katoa had not played for the Warriors under-20 side so far but with a few club games under his belt, it was hoped he would line up in the squad.
Katoa was completing a hospitality course and had a job in the pipeline, his agent said.
