The seven-time Grand Slam singles winner is already a big fan of the 22-year-old's game, admitting that alongside Roger Federer, Barty is the only other player she watches.

"It's such a pleasure to watch Ash play. She's got so many skills she's improved out of sight," Goolagong Cawley said.

"She's getting there now, I think she's quite capable of winning Grand Slam and has proved it already.

"She's got so much more confidence now than I've ever seen and she seems to be really enjoying it out there.

"I don't watch much tennis these days, but I do watch Federer because of his skills and everything and now Ash."

Barty, who is ranked No.9, already has a US Open women's doubles title to her name when she partnered with CoCo Vandeweghe last year.

However, Barty has downplayed the hype around the possibility of winning a Grand Slam telling media in the lead-up that she still has more to learn and do.  

The Ipswich-born player produced some great tennis on Pat Rafter Arena during her Fed Cup World Group semi-final singles rubber against Victoria Azarenka on Saturday night, where she leveled the tie with a 7-6 (7-2), 6-3 victory. 

Goolagong Cawley was particularly excited about the use of Barty's slice backhand against the former world No.1.

"She's got great hands, fantastic, [the slice backhand] was something I enjoyed in my career," she said.

"Every time I saw her do that I thought, 'Oh, that must have felt good'.

"A lot of the players today, with the style and grip, don't seem to like that shot and it's helped her get through a lot of matches."

Fed Cup action continues today (Sunday, April 21) with the reserve singles and possible double rubber.