Reiging US Open champion and former World No.1 Naomi Osaka is set to play her first tournament of the US Summer Hardcourt swing, but before traveling to Toronto to play the Rogers Cup, the 21-year-old Japanese star took to social media to update fans on how she's feeling.

"I've learned a lot about myself and I feel like I grew so much as a person in the past years," she wrote in her Notes app. "I'm really excited what the future looks like on and off the court."

Osaka last played at Wimbledon where, as the No.2 seed, she fell to Yulia Putintseva for the second straight tournament.

"The last few months have been really rough for me tennis wise, but thankfully I'm surrounded by people I love and who love me back," she writes, jokingly adding, "hopefully hahaha."

Osaka began 2019 on the brightest possible note, backing up her US Open win by capturing a second major title at the Australian Open and becoming World No.1 on the WTA rankings.

She later split with coach Sascha Bajin, and has dealt with inconsistencies since Melbourne, reaching the semifinals at just one tournament in the last six months.

"I've put so much weight on the results of my matches instead of learning from them, which is what I 'normally' do."

Still, Osaka, who tweeted similar sentiments last summer before going on to win the US Open, is optimistic that her best is yet to come as she looks ahead to her US Open title defense, crediting the support of family and friends in what has been another extraordinary season for the youngster.

"I've met new people, and been able to do things that I've never considered doing before."

Osaka will next play at the Rogers Cup in Toronto, where she reached the Round of 16 in her debut appearance back in 2017.