That's the opinion of Kyrgios's Canberra-based coach Todd Larkham after the 19-year-old bowed out to world No 18 Tommy Robredo in the third round in New York on Sunday.

Kyrgios claimed the first set and held a break in the second before wily veteran Robredo wore down the teenager to win 3-6, 6-3, 7-6 (4), 6-3.

Kyrgios will return to Canberra before he heads to Perth to begin preparations to partner Lleyton Hewitt in Australia's Davis Cup tie against Uzbekistan from September 12-14.

He is expected to climb into the top 50 in the world rankings and it builds on his superb effort at Wimbledon where he eliminated world No 1 Rafael Nadal on his way to the quarter-finals.

"Wimbledon was great, but this tournament was really positive," Larkham said.

"It just showed in his own mind and everyone that he's the real deal and that Wimbledon wasn't a fluke and he's right there with those top guys.

"He's only a few points away from winning today against a top 20 player and this was very encouraging for him."

Kyrgios raced to a 5-0 lead in the first set and was up 2-0 and had three break points in the second.

He was also up 4-3 in third set tie-break on his serve before losing four straight points.

Robredo showed all of his experience, taking pace off his returns to negate Kyrgios' massive ground strokes and running his opponent around the court to put his fitness to the ultimate test.

"I didn't take opportunities when I had them," Kyrgios said.

"A couple points here and there, that match wouldn't have slipped out of my hands tonight."

Ranked outside the top 800 in the world two years ago, Kyrgios has made a quick ascension to become the sport's next big thing.

He could pass Hewitt next week as Australia's highest ranked men's singles player.

Hewitt is ranked 41, but lost in the first round of the US Open to sixth seed Tomas Berdych.

Kyrgios rose to the occasion of playing under the bright lights of Arthur Ashe Stadium in the main game of the Saturday night session.

"It's massive confidence for me, you gain so much experience from playing on such big courts," Kyrgios said.

"People dream of it.

"It takes them a whole career to get on those courts.

"I'm so used to that surrounding now, so I know what to expect."

After the Davis Cup, Kyrgios has been entered in the Malaysian Open along with tournaments in Tokyo, Shanghai and three indoor events in Europe.

His goal of attaining a seeding for January's Australian Open is within reach.

Larkham knows there is still plenty of room for improvement.

"(Kyrgios) was cramping in the fourth so there's still a lot of work to do physically," Larkham said.

"Robredo defended very well and Nick has a lot to learn.

"He's got to get better coming to the net and serve volley was definitely something he needed today because Robredo was returning a long way back."

With AAP