Defending champion Naomi Osaka, who withdrew from the French Open due to mental issues and skipped Wimbledon, and Roger Federer, who missed the Olympics owing to a knee injury, were named on Wednesday to the U.S. Open tennis field.

The U.S. Tennis Association named the men's and women's singles lineups for the August 30-September 12 event at Flushing Meadows, where spectators will return at 100 percent venue capacity.

The ATP Tour's 103 top-ranked players are entered for New York, with top-ranked Novak Djokovic chasing a calendar-year Grand Slam after a Wimbledon victory that lifted him to level with ninth-ranked Federer and third-ranked Rafael Nadal having men's record of 20 career Grand Slam titles.

Only Rod Laver in 1962 and 1969 and Don Budge in 1938 managed a men's calendar Slam.

Djokovic, who will seek Olympic gold in Tokyo, could become only the second player to win all four Slam singles crowns and Olympic gold in the same year after Steffi Graf in 1988.

Other men's entrants include sixth-ranked defending champion Dominic Thiem, past U.S. Open winners Stan Wawrinka and Marin Cilic, world number two Daniil Medvedev and fourth-ranked Stefanos Tsitsipas.

Britain's Andy Murray, the 2012 U.S. Open champion, was the first player on the alternate list and will gain a spot in the main draw should anyone in the field withdraw.

Sixteen qualifiers and eight wildcards will complete the field.

On the women's side, top-ranked Ashleigh Barty of Australia, who won her second Grand Slam title at Wimbledon, is among 15 Slam singles champions in the field, seven of them in the top 10.

Four-time Grand Slam champion Osaka of Japan, ranked second, is also in the lineup along with 2020 Australian Open champion and world number four Sofia Kenin, fifth-ranked 2019 U.S. Open winner Bianca Andreescu, eighth-ranked Iga Swiatek and former world number ones Garbine Muguruza and Simona Halep.

In all, 100 of the top 104 players in the WTA rankings opted into the event.