A trio of mothers kick off their campaigns at Flushing Meadows on Tuesday with former champions Serena Williams and Kim Clijsters in action on day two along with twice runner-up Victoria Azarenka.
Six-times U.S. Open winner Williams resumes her quest for a 24th major title with her first career meeting against compatriot Kristie Ahn, the world number 96, in the second match at Arthur Ashe Stadium.
Williams, 38, reached the final in 2018 and 2019 but has been stuck on 23 Grand Slam titles, one shy of Margaret Court's singles record, since winning the 2017 Australian Open while pregnant with her daughter Alexis Olympia.
Clijsters, who came out of retirement this year after an eight-year absence during which she gave birth to her second and third children, faces Russia's Ekaterina Alexandrova, the 21st seed, in the first round.
The 37-year-old Belgian wild card could struggle for fitness having withdrawn from last week's warm-up tournament in New York with an abdominal injury.
Clijsters, a three-times U.S. Open champion, has played only two tournaments this year, suffering first round defeats in Dubai and Monterrey before professional tennis ground to a halt due to the COVID-19 pandemic.
Azarenka comes into the tournament as arguably the form player in the women's draw having won the warm-up Western and Southern Open last week, albeit by default after Naomi Osaka withdrew from the final with an injured hamstring.
The 31-year-old Belarusian, who reached the final at Flushing Meadows in 2012 and 2013 but lost to Williams on both occasions, faces Austria's Barbara Haas in her opener.
In the men's draw, 2012 champion Andy Murray starts things off on Arthur Ashe against Japan's Yoshihito Nishioka in what will be the Briton's first Grand Slam appearance since the 2019 Australian Open.
Murray, 33, has twice undergone hip surgery and while he beat world number seven Alexander Zverev last week his fitness could be an issue in the best-of-five sets format.
Second seed Dominic Thiem takes on Spaniard Jaume Munar in the second match on Louis Armstrong Stadium.
(Reporting by Simon Jennings in Bengaluru; Editing by Peter Rutherford)
