Naomi Osaka has opened up on the difficulties she encountered in her time away from tennis after sharing a photo of herself on crutches and unable to walk just one year ago.

Osaka was overcome with emotion after winning her first-round match against Jelena Ostapenko at the US Open on Tuesday, which marked her first victory over a top-10 ranked opponent for four years.

The 26-year-old, a four-time Grand Slam champion, has endured a testing few years after winning the Australian Open in 2021; having followed up that triumph by taking a hiatus from the sport due to mental-health issues before spending the entirety of last season on maternity leave.

Pregnancy wasn't the only thing she had on her plate in 2023, however, as Osaka has also shed light on the injury setback she faced in her recent time away from tennis.

In a shocking post on her Instagram story, the Japan-born star shared a photo of herself on crutches after being left unable to walk 'without pain' as recently as last September.

'I've been asked why I was so emotional yesterday and honestly if you don't even included coming back from pregnancy, New York being my home etc, this was me a year ago,' she wrote alongside the picture.

'I legitimately couldn't walk without pain and I didn't know if I could play at a high intensity anymore. So yeah this sport means a lot to me.' 

Osaka, who been open about her struggles with depression in the past, saw her ranking plummet to No. 88 prior to this year's US Open, where she entered as a wild card.

She has not made it past the third round of a Grand Slam since her Australian Open win three-and-a-half years ago, which is why Tuesday's opening victory at Flushing Meadows meant so much.

'I mean honestly it's like a combination of a lot of different things,' Osaka told reporters about the emotional scenes after her win. 

'I grew up here, so just seeing kids, and then remembering my daughter, but seeing kids coming and watching me play and just remembering that I was a kid, I guess a long time ago, made me very emotional.

'Then also just remembering that I came and watched Coco [Gauff] play her semis [last year] and I was in the audience, and I didn't know if I was going to be able to play again at this level, and just to play Ostapenko who is such a great player and win that match means a lot to me.'

Osaka is now gearing up for her second-round match against Czechia's Karolina Muchova on Thursday night.

If she prevails again in New York, the two-time US Open winner will be one victory away from her furthest run in a Grand Slam for three years.