Two-time Australian Open champion Naomi Osaka admits she needs to set realistic goals as she continues her return to the WTA Tour after giving birth to a baby girl last year.

Osaka missed the entire 2023 season, having announced last January she was pregnant with her first child.

She gave birth to Shai in July and later in the year confirmed she would return to the tour, with the Australian Open set down as one of her first tournaments.

Osaka, who lifted the trophy at Melbourne Park in 2019 and 2021, lost in the first round on Monday night, going down 6-4, 7-6 (7/2) to France's 16th seed Caroline Garcia.

She arrived in Melbourne with only two tour-level matches under her belt, having lost in the second round of the Brisbane International earlier this month.

After 15 months away from professional tennis, few expected Osaka to beat the talented Garcia, who reached the US Open semifinals in 2022.

The loss made the Japanese former world number one reflect that she could not expect too much of herself in the early stages of her comeback.

"I have to tell myself, 'Hey, like six months ago you were pregnant,' stuff like that," Osaka told her post-match media conference.

"Of course, there's a voice in my head that is [saying], 'Who are you to think you can come back and immediately start winning matches?'

"I don't know. I kind of always expect myself to stand a chance, anyway. So I guess just being nicer to myself is like a key thing that I learned in my time away.