Tomljanovic will open proceedings on Saturday against French No.1 Mladenovic in a high-pressure outing just weeks after becoming eligible to represent Australia.
While Tomljanovic is Australia’s second-highest ranked female player behind Barty, her selection is still something of a leap of faith given the highly-experienced Stosur boasts the most singles wins for Australia in Fed Cup history.
Spearheaded by French Open champion Barty, Australia will start warm favourites to claim a drought-breaking victory.
But Mladenovic and Garcia are formidable opponents, meaning there is every chance the contest will go down to a doubles showdown on Sunday.
Mladenovic had a close look at Barty during last week’s season-ending WTA Finals in Shenzhen, China, where the top seed took out the singles title and the Frenchwoman partnered with Hungary’s Timea Babos to win the doubles.
FED CUP FINAL ORDER OF PLAY
Tomljanovic (AUS) v Mladenovic (FRA)
Barty (AUS) v Garcia (FRA)