Switzerland's Roger Federer leaves the court after being defeated by Poland's Hubert Hurkacz during the men's singles quarterfinals match on day nine of the Wimbledon Tennis Championships in London, Wednesday, July 7, 2021. (AP Photo/Kirsty Wigglesworth)

Switzerland's Roger Federer leaves the court after being defeated by Poland's Hubert Hurkacz during the men's singles quarterfinals match on day nine of the Wimbledon Tennis Championships in London, Wednesday, July 7, 2021. (AP Photo/Alberto Pezzali)

Poland's Hubert Hurkacz greets Switzerland's Roger Federer after defeating him in the men's singles quarterfinals match on day nine of the Wimbledon Tennis Championships in London, Wednesday, July 7, 2021. (AP Photo/Kirsty Wigglesworth)

Switzerland's Roger Federer wipes his face with a towel during the men's singles quarterfinals match against Poland's Hubert Hurkacz on day nine of the Wimbledon Tennis Championships in London, Wednesday, July 7, 2021. (AP Photo/Kirsty Wigglesworth)

Switzerland's Roger Federer plays a return to Poland's Hubert Hurkacz during the men's singles quarterfinals match on day nine of the Wimbledon Tennis Championships in London, Wednesday, July 7, 2021. (AP Photo/Kirsty Wigglesworth)

Switzerland's Roger Federer wipes his face with a towel during the men's singles quarterfinals match against Poland's Hubert Hurkacz on day nine of the Wimbledon Tennis Championships in London, Wednesday, July 7, 2021. (AP Photo/Kirsty Wigglesworth)

Switzerland's Roger Federer leaves the court after being defeated by Poland's Hubert Hurkacz during the men's singles quarterfinals match on day nine of the Wimbledon Tennis Championships in London, Wednesday, July 7, 2021. (AP Photo/Alberto Pezzali)

Switzerland's Roger Federer greets Poland's Hubert Hurkacz at the end of the men's singles quarterfinals match on day nine of the Wimbledon Tennis Championships in London, Wednesday, July 7, 2021. (AP Photo/Alberto Pezzali)

FILE - In this July 7, 2021, file photo, Switzerland's Roger Federer wipes his brow during the men's singles quarterfinals match against Poland's Hubert Hurkacz on day nine of the Wimbledon Tennis Championships in London. Federer pulled out of the upcoming hard-court tournaments in Toronto and Cincinnati on Thursday, Aug. 5, 2021, citing lingering issues with his surgically repaired knee and shedding doubt on his status for the U.S. Open. (AP Photo/Kirsty Wigglesworth, File)

FILE - In this July 7, 2021, file photo, Switzerland's Roger Federer plays a return to Poland's Hubert Hurkacz during the men's singles quarterfinals match on the ninth day of the Wimbledon Tennis Championships in London. Federer is going to miss the U.S. Open and be sidelined for what he said will be “many months” because he needs a third operation on his right knee. Federer announced the news Sunday, Aug. 15, 2021, via a video message on Instagram. He said he wil be “out of the game for many months.” (AP Photo/Kirsty Wigglesworth, File)