New York, New York – Naomi Osaka has revealed how she is left "muddled" by struggling to divorce tennis from her personal life.

Osaka withdrew from the French Open for mental health reasons in May after being threatened with expulsion over refusing to fulfill media duties.

The four-time grand slam champion missed Wimbledon but returned to play at the Olympics in her native Japan last month, and also lit the Olympic cauldron at the opening ceremony.

Osaka, who broke down in tears in Cincinatti earlier this month at her first press conference since withdrawing from the French Open, is set to defend the US Open singles title she won in New York last year.

Asked ahead of the tournament whether she saw the tennis court as her sanctuary, Osaka replied: "It would be nice if there was that line for me, but no."

"I’m the type of person that everything is sort of the same. So, like, I feel like maybe you could see it earlier on in my career."

"If there was something that was not right in my personal life, you could kind of see it in my playing."

"So it would be really cool if I could draw that line and be able to be like a robot Superman that could go on the court, focus just on tennis."

"But, no, I’m the type that kind of focuses on everything at one time. That’s why, like, everything is sort of muddled to me."

Osaka has said in the past that she feels self-conscious at times about going out in public.

She will be in the spotlight at the 2021 US Open, which starts on Monday, as the defending champion and with crowds back after the coronavirus pandemic.

"It will definitely feel a bit different," Osaka said.

"I don’t really know how to describe it, but I kind of had to get over the feeling of people’s gazes feeling a bit different to me."

"At the same time I started to tell myself that it is what it is. I can’t really change people’s perception on me."

"It might make me feel a little bit nervous. But first rounds always make me feel a little nervous."

"Maybe I can just attribute it to that. I guess I’ll find out when I’m in that situation."

On being back at Flushing Meadows, Osaka said: "It feels really nice. I feel like whenever I come here, of course I have memories of winning before."

"But I think the biggest memory that comes back to me is being a little kid, running around the entire site."

"I don’t know if that may be the reason why I play so well here, but there’s definitely a lot of nostalgia."

"I played literally no tournaments before that (Cincinnati) match and I’m not declaring that I’ll do amazing here."

"But I feel pretty confident with where I am right now and hopefully it will work out in the end."