Aussie doubles duo say pressure is off

Casey Dellacqua and Ashleigh Barty say they are among the best doubles teams in the world, but argue it's World No.1 team Martina Hingis and Yung Jan-Chan with all the pressure on them.

The Australian duo will continue an amazing comeback story when they face Johanna Larsson and Kiki Bertens in the first round of the year-ending WTA Finals in Singapore.

The doubles begin on Thursday, with Dellacqua and Barty the third seeds.

Unlike the singles event running parallel, the doubles is a single elimination event.

Not that the Aussies are too fazed.

"We have to bring our best ... but a few teams have had some great results this year, with Chan and Hingis probably winning the most amount of matches at the big tournaments," Dellacqua told AAP.

"But when it comes to a format like this, it's really about who can put their best tennis together on the day."

Qualifying for Singapore is a just reward for the duo, who made the French Open final this year, only to succumb 6-2 6-1 to top seeds Bethanie Mattek-Sands and Lucie Safarova in 66 minutes.

The Fed Cup teammates have lost finals at all four majors, having been runners-up at the Australian Open, Wimbledon and US Open in 2013 - and are yet to win a grand slam women's doubles title.