Barty's focus is now on the Australian Open at Melbourne Park, which will resume its traditional January time slot in 2022 after a pandemic-enforced delay this year.
The Australian's withdrawal from the women's team tennis competition formerly known as the Fed Cup comes hot on the heels of her decision to sit out this month's Indian Wells tournament in California.
Officials gave no reason for Barty's decision to pull out of next month's women's draw which was already suffering from the absence of several top-ranked players, including Naomi Osaka and Serena Williams.
Four-time Grand Slam champion Osaka fell from fifth as Barty remains top and French Open winner Barbora Krejcikova climbed to a career high of fifth.
The 18-year-old became the first player to emerge from qualifying to win a Grand Slam tournament when she beat another teenager, 19-year-old Canadian Leylah Fernandez, 6-4, 6-3 on Saturday.
Americans Shelby Rogers, Jenson Brooksby and Reilly Opelka won on Day 6 of US Open with Novak Djokovic taking another step towards calendar Slam.
Barty won 11 of 14 games after dropping the first set, was then broken twice while serving for the match and eventually dropped a shocker to American Shelby Rogers 6-2, 1-6, 7-6 (7/5).
Reigning Wimbledon champion Barty won 11 of 14 games after dropping the first set, only for Rogers to capture five of the last six games for a shocking 6-2, 1-6, 7-6 (7/5) triumph.
US Open on Thursday witnessed largely smooth sailing for the favourites while doubles presented the surprise results.
Barty, 25, added Wimbledon to the 2019 French Open in her Slam trophy case but refuses to accept momentum as a reward.
The 34-year-old Serbian cruised past 121st-ranked Dutchman Tallon Griekspoor 6-2, 6-3, 6-2 at Arthur Ashe Stadium to book a third-round date with 2014 US Open runner-up Kei Nishikori
Day 2 of US Open had its fair share of drama for some while it was smooth sailing for the big guns Novak Djokovic, Ashleigh Barty, Alexander Zverev - to name a few.
US Open 2021: Novak Djokovic launches calendar Slam quest with win; qualifier stuns Pablo Carreno Busta
Fourth-seeded Zverev, coming off Japan gold and a title two weeks ago at Cincinnati, dispatched American Sam Querrey 6-4, 7-5, 6-2 in a first-round match at Arthur Ashe Stadium.
At the Noosa Tennis Club, not far from where she and her husband, Roger Cawley, live, Goolagong Cawley held court with a bunch of local schoolchildren and helped cut the ribbon for a mural which will double as a hitting wall.
US Open 2021: Novak Djokovic eyes history, fans return to Flushing Meadows, and other talking points
US Open, the last major of the year, gets underway today with Novak Djokovic chasing twin records, Naomi Osaka is back in familiar territory and fans frolicking the stadiums.
US Open 2021 women's singles preview: Ash Barty looking to cap off excellent season, Naomi Osaka to make winning return?
Ahead of the US Open, Firstpost.com takes a look at the women's singles draw and, with equal parts of bravery and naivete, attempts to determine the potential outcome of all four quarters.
Barty is back and so are spectators after empty stands last year due to Covid-19. She's excited about playing before full-capacity crowds after sitting home last year.
US Open 2021: Novak Djokovic faces potential Wimbledon final rematch against Matteo Berrettini in quarter-finals
Under a men's singles draw released Thursday by the US Tennis Association, the 34-year-old Serbian top seed was placed in a draw quarter that could see him meet Australian fourth seed Alex de Minaur in the fourth round.
After ousting fourth-ranked Pliskova, Teichmann stands 4-0 this season against top 10 players.
Cincinnati Masters: Medvedev books semis spot with win over Carreno Busta; Barty beats Krejcikova to reach last-four
Medvedev, last week's Toronto champion, won his eighth match in a row as he prepares for a final four contest against compatriot Andrey Rublev.