NICK KYRGIOS gave another scathing assessment of his dedication to tennis after losing in the first round of the US Open. The 22-year-old hurt his right shoulder in the third set of his match against fellow Australian John Millman and fell to a 6-3 1-6 6-4 6-1 defeat.

Asked afterwards if he would be continuing his partnership with coach Sebastien Grosjean, Kyrgios said: "I'm not good enough for him. 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 training sessions. There are players out there that are more dedicated, that want to get better, that strive to get better every day, the one-percenters. I'm not that guy."

Kyrgios was clearly disconsolate at having another physical issue after playing so well in Cincinnati two weeks ago, beating Rafael Nadal before losing to Grigor Dimitrov in the final.

He complained of his right arm feeling dead after hurting it on a serve early in the third set. Kyrgios received treatment and a sympathetic ear from the trainer as he explained his frustration but no solution to his problem.

The Australian angrily protested a code violation given after he swore in frustration at his sore arm. It was not heard by umpire Carlos Ramos but reported to him by a line judge.

Kyrgios then received a point penalty when, after dropping serve to lose the third set, he smashed his racket violently on the court. But ultimately his main concern was the state of his body. Having failed to wedge the broken racket into his bag, Kyrgios walked off court holding it with head bowed and boos ringing in his ears, rather summing up his day.

Asked if he wanted to be more dedicated, Kyrgios said: "Probably not, honestly not. In Cincinnati, I was not doing anything different. I was probably less dedicated than I was this week. I was playing basketball every day for two hours. I was going to get ice cream, getting a milk shake every day. I was less dedicated. And this week I was dedicated, and my shoulder starts hurting."

As for what he does next, a dejected Kyrgios said: "I don't know. I keep letting people down."

Kyrgios looked to have turned a corner earlier this season when he posted a series of impressive results but he has been unable to stay healthy over the past few months. He aggravated a hip injury at Queen's Club in June and retired during three successive matches, including his opener against Pierre-Hugues Herbert at Wimbledon.

Kyrgios has won just two grand slam matches all season, one at the Australian Open and one in Paris, and he added: "I have had a diabolical year at the slams. It doesn't surprise me. It's just the story of my career, really. I will have good weeks; I'll have bad weeks. It's just a rollercoaster.

"Obviously I'm disappointed I lost today but it's not the end of the world. I will get over it in probably half an hour. I will get food and watch the matches."

Kyrgios' defeat is potentially good news for Roger Federer, who struggled through a five-set win over Frances Tiafoe in round one and could have faced the Australian in the fourth round.

Elsewhere, there were first-round wins for Grigor Dimitrov, Dominic Thiem, David Goffin, Juan Martin del Potro, Gael Monfils and Tomas Berdych but Richard Gasquet was beaten by Leonardo Mayer.

Aljaz Bedene suffered a disappointing loss to Andrey Rublev in the opening round of the US Open.

The British number three was outplayed throughout by his young Russian opponent and slid to a 6-1 6-4 6-4 defeat in an hour and 42 minutes.

It has been an excellent season for Bedene but he went into the tournament having played just one match since Wimbledon after taking a break for his wedding to pop star girlfriend Kimalie.

He certainly looked rusty in the early stages against Rublev, at 19 one of the best young talents in the game.

Bedene turned things round after losing the first set 6-1 in their only previous meeting earlier this year but this time Rublev, ranked five places below his opponent at 53, was far too consistent.

When Bedene, who has only ever won one main draw match at Flushing Meadows, dropped serve in the seventh game of the third set, the writing was on the wall.

The 28-year-old's defeat leaves Kyle Edmund and Cameron Norrie, both of whom were due to play their second-round matches later on Wednesday, as the only British players left in the singles draws.

Rublev moves through to a second-round meeting with seventh seed Grigor Dimitrov.