Seeing a friendly face is supposed to be a good thing.

Yet when Aryna Sabalenka and Paula Badosa take to the court for their Australian Open semi-final on Thursday, it may only add to the pressure.

The pair are close friends with Sabalenka going so far as to call Badosa her "soulmate" in Stuttgart last year.

"I love Paula very much," the 26-year-old Belarusian said.

"She is an incredible person. It is very important to have friends on the circuit, so when you find someone who you feel is your soulmate, it is the best thing that can happen to you."

Their friendship has grown over the past few years with the pair practising together and wearing matching outfits during the 2024 US Open, as well as posting about each other on social media.

"We realised that we had very similar personalities and we get along very well, and that we're both very, very competitive," Badosa told the Tennis Channel's Inside-In podcast, external in March.

"It's very nice for me having a friend on tour because it's very tough to find."

But with a place in the final at stake, that friendship will have to be put on hold in Melbourne.

This is not the first meeting between the two - they have played eight times before, with Sabalenka winning the past six - but it is comfortably the most high-profile.

World number one Sabalenka is bidding to win a third straight Australian Open title, while it is 27-year-old Badosa's first time in the last four of a Grand Slam.

The Spaniard shocked sixth seed Coco Gauff in the quarter-finals as her remarkable recovery from a back injury, that she feared would force her to retire only a year ago, continues.

"It's tough to play your best friend," Sabalenka said after beating Badosa in Stuttgart.

However, difficult as it may be, once they walk out on Rod Laver Arena, all sentiment will be put to one side.

"We know how to separate things," Badosa added.

"We decided a long time ago that off the court we are friends, while on the court she really wants to win, I really want to win," said Sabalenka, who beat Anastasia Pavlyuchenkova in the quarter-finals.

"So on the court we are competitors and there is no place for friendship."