Two of the world's top tennis players, Roger Federer and Rafael Nadal, both have confirmed the dates and events for their return. Federer will participate in the Laver Cup in London in September and Swiss Indoors in Basel in October.

"10-time singles champion and hometown hero Roger Federer has announced his comeback to the stadium at St. Jakobshalle. The Swiss all-time great has confirmed his initial agenda will include the Laver Cup in London followed by the Swiss Indoors in Basel," Swiss Indoors said in a statement.

Having won 20 Grand Slam titles in his career, 40-year-old Federer has not appeared in any competitive match since he lost to Hubert Hurkacz 6-3, 7-6 (4), 6-0 in the Wimbledon quarterfinals on July 7, 2021. He announced to undergo knee surgery last August before withdrawing from all of the following tournaments, including the U.S., Open in 2021 and the Australian Open this year.

Federer has won the Swiss Indoors title 10 times, including doing so in three consecutive years between 2017 and 2019. The event was canceled in 2020 and 2021 because of COVID-19. The last time Federer won a Grand Slam title was at the Australian Open in 2018.

Nadal, who has won a record 21 Grand Slam championships, confirmed his return at the Madrid Open beginning on Sunday.

"Despite arriving with minimum preparation and [knowing] that it will be difficult, I am very excited to play and to play in front of a home crowd, even with few chances [to win]," Nadal posted on Twitter on Tuesday. "I will try to do it the best I can. See you in Madrid."

Nadal's last match was a 6-3, 7-6 (5) loss to Taylor Fritz in the Indian Wells Masters final on March 20. Nadal spent the following month recovering from a rib injury. He has won the Madrid Open title five times; the last time was in 2017.

The other superstar chasing his 21st Grand Slam title, Novak Djokovic, is cleared to compete at the Wimbledon Championships after the tournament organizers said there won’t be a COVID-19 vaccination mandate for players.

"The requirements set up do not include mandatory vaccination," All England Club CEO Sally Bolton said at a press conference on Tuesday. "It will not be a condition of entry for the championships this year."

Djokovic missed the Australian Open in January because he wasn't vaccinated. Neither was he at any tournament in the U.S. for the same reason in March. He beat Matteo Berrettini in the Wimbledon Championships final 6-7(4-7), 6-4, 6-4, 6-3 in 2021.

World No. 2 Daniil Medvedev of Russia is banned from Wimbledon this year. So is women's world No. 4 Aryna Sabalenka of Belarus.