'Mature' Osaka reflects on breakthrough year

'I feel like I'm more... I wouldn't say confident but I'm more, like, I have inner peace. I don't know. Like zen. I don't really want to use words I don't know. But like I can go inside myself and be like peaceful, so I think maybe in the beginning of the year I was very uncertain with what I was doing. But now I feel a bit more calm.'

Naomi Osaka crashed out of the WTA Finals when a tight hamstring consigned the US Open champion to a third straight defeat in her tournament debut on Friday, but the rising Japanese star was still keen to reflect on what has been a brilliant campaign.

The 21-year-old made her Grand Slam breakthrough in New York last month and followed up with a run to the Pan Pacific Open final in Tokyo and the China Open semi-finals, but a leg injury in Singapore ruined any chance she had of adding to that success.

"It's been a crazy year, I think," Osaka told reporters after retiring from her final group match following the loss of the first set to Kiki Bertens on Friday.

"It started in Australia with a run to the fourth round when I did better in a Grand Slam than I have done before. And then, of course, I won in Indian Wells before doing nothing until the US Open basically," she added with a smile.

"And then from US Open a lot has happened, so I don't know. It feels like it went up and then it went sort of down and then in a straight line and then went up again.

"For me, it's just been a lot of new experiences. I'm very grateful that I was able to have the opportunities that I had. For sure, I feel like I have matured. I hope I can say that."

The emotional roller-coaster of her Flushing Meadows victory against Serena Williams, when the American became embroiled in a furious row with the chair umpire, had helped in her development, Osaka said.

"I witnessed some stuff. That's for sure," she added.

"I feel like I'm more... I wouldn't say confident but I'm more, like, I have inner peace. I don't know. Like zen. I don't really want to use words I don't know.

"But like I can go inside myself and be like peaceful, so I think maybe in the beginning of the year I was very uncertain with what I was doing. But now I feel a bit more calm."

Looking ahead to her off-season, Osaka said she was glad to be getting some time off the court but worried that she might soon grow bored of the inactivity.

"I was told I shouldn't really do much. I should just rest for a few weeks. So I think that's what I'm going to do," she said of the injury.

"I'm looking forward to going back home (to Florida). I haven't been home since the US Open. So definitely looking forward to going back.

"I feel like I'll rest. But for me, whenever I rest, the first day I'm happy I'm home because I'm just laying down and not doing anything, but then the second day I'm really bored and I start thinking I want to play again.

"I have never really had a vacation. So, yeah, I guess it will be interesting to see how that goes."