Nick Kyrgios bundled out of US Open by fellow Aussie John Millman

Nick Kyrgios claimed he had no devotion to tennis and probably never would after completing a “diabolical” grand slam season with a drama-charged first-round US Open defeat.

Kyrgios complained of a “dead” shoulder during his 6-3 1-6 6-4 6-1 loss to fellow Australian John Millman before revealing far deeper concerns during an extraordinary post-match press conference.

Shattered by his latest flop, the tempestuous talent admitted his coach deserved better when asked if he would continue working with Frenchman Sebastien Grosjean beyond the Open.

“I don’t know, honestly. I’m not good enough for him,” Kyrgios said.

“He’s very dedicated. He’s an unbelievable coach. He probably deserves a player that is probably more dedicated to the game than I am. He deserves a better athlete than me.

“I’m not dedicated to the game at all.

“He’s helped me a lot, especially with the training, in training sessions, but there are players out there that are more dedicated, that want to get better, that strive to get better every day, (do the) the one-percenters. I’m not that guy.”

After winning an unprecedented 20 from 20 matches against lower-ranked or unseeded rivals at grand slams, Kyrgios has since suffered upset losses at five straight majors.

His troubles have coincided with the surfacing of a hip injury at last year’s US Open when he retired mid-match in the third round before the same issue forced him to abandon his Wimbledon campaign.

Kyrgios said his latest shoulder problem, which first emerged early in the third set against Millman, came out of the blue.

“I have had a diabolical year at these slams. It doesn’t surprise me,” he said.

“It’s just the story of my career, really. I will have good weeks; I’ll have bad weeks. It’s just a roller-coaster.”

The world No.17 enjoyed one of his best weeks a fortnight ago when he reached his first Masters 1000 final in Cincinnati.

Now he feels exasperated.

“In Cincinnati, I was not doing anything different. I was probably less dedicated than I was this week,” Kyrgios said.

“I was playing basketball at Lifetime Fitness every day for two hours. Like I played an hour of basketball before I played David Ferrer in the semi-final.

“I was going to ice cream, like this Graeter’s place getting a milkshake every day. I was less dedicated.

“And this week I was dedicated, and my shoulder starts hurting. I don’t know.”

Kyrgios’s premature exit follows a first-round loss at Wimbledon and second-round defeats in Paris and Melbourne.

“I don’t know. I don’t know. I keep letting people down,” he said.

Despite his abject disappointment, Kyrgios said he planned to press ahead with plans to lead Australia into battle against Belgium in the Davis Cup semi-finals this month in Brussels.