The boy is part of the Jets Academy under-15 team that played against the Stanmore Hawks at Arlington Oval in the inner-south-west Sydney suburb of Dulwich Hill on Saturday.

Mr McKinna said it was too early to say whether the academy should stop playing in Sydney.

"We don't know yet the boy's got it from football," he said. "Everybody's jumping to that conclusion. We can't jump in and make decisions now. We need to find out the facts."

An older relative of the player, a man in his 20s, has also tested positive.

The Jets under-14s, 15s and 16s are due to play against Canterbury-Bankstown FC at The Crest Athletic Centre at Georges Hall on Saturday.

The club said no training would go ahead this week and games would be reviewed pending advice from Football NSW and NSW Health. The under-15s players are in self-isolation as close contacts.

The teams have travelled twice to Sydney since the NSW National Premier Leagues 2 competition resumed in early July.

The Jets also have an under-13 boys' team, junior girls' squads and under-18 and under-20 male teams playing in Sydney.

The boys' under-13s, 14s, 15s and 16s are all leading their competitions undefeated after six rounds, but Mr McKinna said decisions about whether to keep playing would be made purely on health grounds.

"We'll weigh up over the next couple of days," he said.

"It's not a football thing; it's a health decision. If the health board want us to stay out of Sydney, well, we'll have to make those decisions based on the medical considerations, for the health of the players."

Newcastle MP Tim Crakanthorp, whose son is a member of the Jets under-15s team but did not travel to Sydney due to injury and is not classed as a close contact, said sports should reconsider playing outside the region.

"A lot has changed in the Hunter in just the last couple of days, and I think that, if they haven't already, all sporting codes should seriously reconsider travelling to Sydney," he said.

"Many sports are already restricting themselves to their regions and districts, and it is something that should be considered."

The player who tested positive did not train with his side at Hunter Sports High on Monday.

Lambton Jaffas first-grade coach James Pascoe, a teacher and sports director at the school, could not attend his side's catch-up game against Valentine at Cahill Oval on Wednesday night and watched the match at home.

Some junior teams at Kotara have cancelled training due to links with St Pius X High School at Adamstown, where the Jets player goes to school, and Newcastle Hockey Centre has closed until Monday and cancelled this weekend's games as a precaution.

Northern NSW Football boss David Eland said the involvement of St Pius had the largest potential to disrupt club football this weekend.

He said NNSWF was following the health advice that any students, teachers or parents who were at the school on Monday should be self-isolating until told otherwise, which meant no training or playing.

In an email update, Hunter Sports High School principal Rachel Byrne advised players in the Jets under-15 team who attended the school would be in self-isolation for 14 days in line with heath advice.

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