I've done nothing in my career: Kyrgios

Nick Kyrgios has confessed to having accomplished nothing in his turbulent tennis career after being handed a grand slam reality check at Flushing Meadows.

"I have been around for about four years now. I have barely done anything," Kyrgios, who fell victim to a virtuoso display from Roger Federer in the third round of the US Open in New York, said.

Federer's 6-4 6-1 7-5 clinic left Kyrgios in a reflective mood.

After announcing his arrival on the international stage with a spectacular centre-court ambush of world No.1 Rafael Nadal at Wimbledon in 2014, Kyrgios has just two grand slam quarter-final appearances, plus four ATP titles, on his CV.

Both last-eight showings at the majors came when he was a teenager.

"I think I can do a lot more. It's all mental with me, I think," Kyrgios said.

"If I want it enough, I have a coaching option, psychology option.

"There is a lot more things to explore.

"But, I mean, obviously I want to achieve more in the sport. I don't think I have done anything."

But despite microphones picking up the 23-year-old ranting about needing to hire a coach during a second-set meltdown against Federer, Kyrgios says he's in no rush to appoint a mentor after flying solo for almost a year - and much of his career.

"I think more of my tennis is more to do with the mental side of things rather than technique or tactics or anything like that," he said.

Coach or not, Kyrgios admits he could

"Just the way he goes about things, I could take a leaf out of his book," he said.

"The way he behaves on court, you his demeanor, I could definitely take away.

"We're two very different characters. I don't want to change myself too much, but I could definitely take away things he does in certain situations.

"He's the ultimate role model to anyone who wants to play."

Kyrgios will depart the season's final grand slam provisionally ranked No.27 in the world, just 15 spots higher than inspired countryman John Millman.

The 29-year-old Millman earned his own shot at Federer on Monday with a breakthrough 6-4 4-6 6-1 6-3 third-round win over Mikhail Kukushkin.

Millman's victory vaulted him into the second week of a major for the first time.

"Is a great feeling," he said.

"I'm extremely excited. It was a goal of mine to make second week of a grand slam. I have managed to do so.

"I will relish the opportunity."

Teenage sensation Alex de Minaur joined Kyrgios in bowing out, but in far more gracious fashion, going down 4-6 3-6 6-3 6-4 7-5 in a five-set cliffhanger against seventh-seeded 2014 Open champion Marin Cilic.

HOW THE AUSSIES FARED ON DAY SIX OF THE US OPEN (PREFIX DENOTES SEEDING):

Men's singles, third round

John Millman bt Mikhail Kukushkin (KAZ) 6-4 4-6 6-1 6-3

30-Nick Kyrgios lost to 2-Roger Federer (SWI) 6-4 6-1 7-5

Alex de Minaur lost to 7-Marin Cilic (CRO) 4-6 3-6 6-3 6-4 7-5