Victorian Premier Dan Andrews is under pressure to not only end the state's snap five-day lockdown but also allow fans back at the Australian Open.

Andrews is offering no guarantees, saying not all restrictions will be lifted at midnight on Wednesday.

Barty plays Czech world No.27 Karolina Muchova in Wednesday's opening women's quarter-final encounter.

Australia's world No.1 is just two wins away from a place in Saturday's final and even one of her potential opponents in the title match is pleading with Andrews to open the gates to fans.

Third seed Naomi Osaka says she'd loved to play Barty for the trophy in front of as many fans as possible at Rod Laver Arena.

"I would want people to come," said Osaka, the 2019 champion.

"I feel that's something for (Barty) that would be a big memory.

"Even for me, I've played finals before with no crowd and it's definitely memorable.

"But I'm sure for her, if she reaches the final and there's no crowd, it would be memorable but kind of in a sad way."

Osaka is already through to the final four after ousting Hsieh Su-Wei in straight sets on Tuesday.

Barty and Muchova will be looking to join the Japanese ace and seven-times champion Serena Williams in the semi-finals.

As will Jennifer Brady and Jessica Pegula, who square off in the last women's quarter-final on Wednesday.

The last two men's quarter-finals will also take place, after Russian qualifier Aslan Karatsev and world No.1 and defending champion Novak Djokovic advanced on day nine.

Fourth seed Daniil Medvedev and seventh seed Andrey Rublev clash in an all-Russian affair before world No.2 Rafael Nadal plays Greek superstar Stefanos Tsitsipas on Wednesday night.

Australian Associated Press