Naomi Osaka insisted her initial focus was not on winning the Australian Open despite a change in expectations.

Osaka, 21, enters the year's first grand slam after a stellar 2018 that included winning the US Open in September.

The Japanese star had not gone beyond the fourth round of a major before that run, having made the last 16 in Melbourne last year.

Asked about her expectations, Osaka said it was best not to think too far ahead.

"I have to take it one step at a time. No one wants to lose in the first round of a slam, I think. That would be my immediate goal," she told a news conference on Saturday.

"From there, I've been in the third round 100 million times already. That would be my next goal. Hopefully semis after that. Then I can think about, like, the finals and winning."

"There's so many good players in this draw, I know that everyone wants to win this tournament. My first, immediate thought isn't to win."

Osaka will face Magda Linette in the first round, and her only previous meeting with the Pole ended in a three-set defeat in Washington last year.

The world number four recalled that encounter and said making fewer mistakes would be a key.

"It was the first match of my three-match losing streak. I thought that she played really well. She's a very consistent player. She doesn't really miss balls," Osaka said.

"At the time it was sort of me that was making a lot of unforced errors. I think that's something that I need to keep in mind the next time I play her, which is on Tuesday."

"I feel like I have to practice a lot of returns and stuff."