Nick Kyrgios is more concerned about his dangerous third-round US Open opponent than being sent on an enforced holiday to consider his conduct.

And with sound reason – tennis officials can’t get enough of him.

In a sign of how much the sport needs him, the young volatile Australian Kyrgios is the hottest ticket in town in New York.

The headline-grabber’s duel with Russian dynamo Andrey Rublev on Saturday has been scheduled as the second night match – prime time under lights at Arthur Ashe Stadium.

US Open organisers also scrambled to move the controversial drawcard from Court 5 to Ashe – the sport’s biggest stadium – for his first-round doubles match, which he won with Romania’s Marius Copil, on Friday.

For all his sins, ATP chiefs investigating Kyrgios’ two “major offences” that potentially carry a suspension of up to 12 months each have already decided not to boot the combustible star out of the Open.

Little wonder he said he wasn’t worried, or expecting any calls from above any time soon.

But Kyrgios knows Rublev is certainly capable of sending him packing from New York.

The 21-year-old this month added Roger Federer to his growing list of prized 2019 scalps, which also includes fellow grand slam champions Stan Wawrinka and Marin Cilic.

Rublev also reached the quarter-finals last year at Flushing Meadows before pushing Kyrgios to the limit in a three-set thriller in his home tournament in Moscow.

‘It’s going to be tough’

Kyrgios is rightfully wary as he eyes a first-time foray to the second week in New York.

“Yeah, he’s a very good player,” Kyrgios said ahead of their second career meeting (about 11am Sunday AEST).

“He’s a young, fearless player who has been playing really well the last couple weeks. Obviously he had that win over Roger.

“He plays big from both sides. He’s a great player. He’s going to have a great future.

“I mean, I played him once in Moscow. It was an incredibly tough match. So it’s going to be tough, for sure.”

Fingers crossed Kyrgios doesn’t get distracted. Photo: AAP

Should he pass his biggest test of the tournament so far, Kyrgios could face boom Australian youngster Alexei Popyrin for a berth in the quarter-finals.

Popyrin, 20, takes on Italy’s 24th seed Matteo Berrettini looking to reach the last 16 at a slam for the first time.

“I know a little bit about him. He’s got a big serve, big forehand – kind of similar to my game actually. That’ll be interesting,” the 20-year-old said.

Kyrgios and Popyrin are hoping to give Australia three men in the last 16 at Flushing Meadows for the first time in 31 years, when Darren Cahill, John Frawley and Mark Woodforde all made it that far.

De Minaur’s 6-2 6-4 2-6 6-3 victory over seventh-seeded former Open runner-up Kei Nishikori thrust the 20-year-old into the last 16 of a slam for the first time.

The last time Australia has even two men in the fourth round of the US Open was 2001 when Lleyton Hewitt won the title and two-time champion Pat Rafter also reach the final 16.

-AAP