(Photo by Al Bello/Getty Images)

The U.S. Open begins Monday with some of the world’s best tennis players ready to take the courts at Flushing Meadows.

World No. 1 Ashleigh Barty, looking to build off of her win at the Western & Southern Open last weekend, will face former world No. 2 Vera Zvonareva in the first round. In another quarter of the bracket, defending U.S. Open champion Naomi Osaka takes on Czech tennis player Marie Bouzková in her opener and could meet three-time Grand Slam champion Angelique Kerber in the fourth round.

The withdrawals of Venus and Serena Williams mark the end of an era. For the first time since 2003, neither Williams sister will compete in the year’s final Grand Slam. Top-ranked American Sofia Kenin also pulled out of the tournament after testing positive for COVID-19 despite being fully vaccinated.

However, multiple American teenagers are waiting in the wings, led by 17-year-old Coco Gauff.

When is the U.S. Open?

The 2021 U.S. Open begins Monday and concludes on Sunday, Sept. 12. (All times below are Eastern.)

First round: Monday at 11 a.m.

Second round: Wednesday, Sept. 1 at 11 a.m.

Third round: Friday, Sept. 3 at 11 a.m.

Quarterfinals: Tuesday, Sept. 7 at 11 a.m.

Semifinals: Thursday, Sept. 9 at 7 p.m.

Final: Saturday, Sept. 11 at 4 p.m.

How to watch:

The 2021 U.S. Open will be broadcast on ESPN and streamed on ESPN.com and through the ESPN app.