"He was a young kid playing two or three grades up," remembers Paul Hobson, long-time director of football at the North Shore club. "You never really know at that age but you could see he had a special talent."
But Tuiloma's background was as working class as you get. Father Koko rose at 5am every day to go to his job at a rubber factory. His mother worked as a cleaning supervisor to help provide for the family. Things were always tight.
"I didn't have flash boots when I was young," says Tuiloma. "I had some old Puma [boots] that I got from the club, spare ones that had been handed down. And I didn't have the football I wanted. I think one of my first balls was from the Two Dollar Shop. It was difficult for my parents to supply me with the things I wanted but they gave me everything they could - that's why I am here today. "
Tuiloma lived in a disciplined environment. "It was a typical Samoan Christian family - I got brought up hard. It was 'go to church every Sunday, come back home after school, never go out' ... but it was good for me to be humble, don't get a big head, respect everyone."
Tuiloma made age-group representative sides and starred for school teams. When he switched to Waitakere City to play in the Nike Cup, coach Neil Emblen gave him his senior debut at the age of 14.
"Usually it is hard to trust young players as defenders but it wasn't a risk with Bill," Emblen says. "He was rock solid and had the maturity to handle it."
Tuiloma later won a full-time scholarship to the Asia Pacific Football Academy in Christchurch, followed by trials at Queens Park Rangers, Burnley and LA Galaxy before inking a deal with Marseille in July 2013. Now he gets new boots supplied every month, tons of training gear and lives in an apartment near the centre of Marseille. But he's never forgotten his origins.
"It's all about my parents - they sacrificed so much," he says. "My father loved fishing but he sold his small boat just to get some money I needed to go on football trips. All their savings went into my football costs."
One of the most poignant moments for Tuiloma came in 2011, when he was flying to Christchurch to take up the APF scholarship.
"I was about to go through security and I asked Mum for some money for the trip," he says. "But she said she had none. That's tough. Every time I talk about that, I get emotional, to be honest. Now I have things I can give back to them."
Tuiloma has progressed well at Marseille, making the massive leap from Northern League football to a fully-professional environment in a country that boasts over two million registered male players. He has impressed Marseille coach Marcelo Bielsa and was good enough to make two first-team appearances off the bench this season.
"He told me to play simple [and] move the ball quickly," said Tuiloma of Bielsa's match-day words. "He said, 'don't hold the ball too long, otherwise they will just take it off you'. French football is very quick."
Tuiloma seems to have a bright future in Europe but, for now, he has the hopes of a nation on his shoulders, in the biggest football tournament this country has hosted.
New Zealand have some handy talents but Tuiloma is the heartbeat of the team. He'll be the defensive shield in front of the back four and will need to provide attacking thrust near the opposition.
"Athletically, he is a great specimen," says Emblen, who is under-20s assistant coach with Darren Bazeley. "He is sharp in his movements and uses his strength well. Then on the ball, he makes good choices. He's always made decisions beyond his years. He's now making the decisions of a 25-year-old."
Tuiloma hasn't played much for the Junior All Whites but led the team to their impressive 0-0 draw with Brazil last June and scored a long-range free-kick in the 2-1 loss to Honduras on Thursday.
"This tournament has been in my head for months. I can't wait for it to start. It's such a big opportunity and an honour to be involved."
