Australian tennis's next big thing, Nick Kyrgios, is taking on the world number one, Rafael Nadal, in Wimbledon's round of 16.

It is, without doubt, the biggest match of the 19-year-old's career.

But for his mum, Nill, it is all too much and she will not be watching.

"I don't watch Nick play. I'm just too nervous. I get too scared. I'm just hopeless – I tend to hide," she told 7.30.

She is at home in Canberra.

Nick's dad George and older sister Hali are in London to watch from the stands.

Kyrgios' childhood coach Andrew Bulley says family support is the young player's secret weapon.

"With the family around he can be himself with no airs and graces," Bully said.

"The tour can be quite combative. Having a family member with him is fantastic."

Bulley says Kyrgios was a terrific young player, but admits he did not always pick him as the most likely to succeed.

"There were other people who might have had a bit more flair or looked a bit more athletic but Nick was always a super competitor,"

"He trained with a better intensity than the other kids. He always turned up and gave it 100 per cent."

It is that attitude which is catching the eye of experts.

Former Davis Cup captain John Alexander says Australia's bright young tennis star could be "the one" to lift Australian tennis out of its torpor.

"There's a lot of talent. There's a lot of big hitting ability. He's courageous, he's a big hitter, he's got all the makings, but he's just 19 years of age, he's got a long way to go," Alexander said.

But he cautions about putting too much weight on Kyrgios' shoulders, ahead of the biggest match of his career.

"It's the legacy of coming from a great tennis nation," he said.

"We keep expecting another Rod Laver, another Ken Rosewall, another John Newcombe. And anyone who shows their face for one minute, anyone who shows their face it's: 'this is the one'."

"In this case it might well be the case."