Two of tennis' biggest stars are in Wimbledon action on Tuesday as Serena Williams returns to singles tennis after a year away as Rafael Nadal begins his quest to win the third leg of a potential calendar Grand Slam.
Women's top seed Iga Swiatek, who has won her past six tournaments, will kick off proceedings on Centre Court at 12.30pm (GMT) against Croatian qualifier Jana Fett.
But all eyes will be on seven-time champion Williams, who faces unseeded Harmony Tan of France in her first singles match since an injury forced her to pull out of her first-round match last year.
Williams, 40, won the last of her Wimbledon singles titles six years ago but reached the final in 2018 and 2019.
The American, who was given a wildcard for this year's tournament, is chasing a 24th Grand Slam singles title that would see her tie Margaret Court's all-time record.
Williams said thoughts of retirement had not been on her agenda during her year-long absence.
"I didn't retire. I just needed to heal physically, mentally. I had no plans. I just didn't know when I would come back. I didn't know how I would come back," she told reporters Saturday.
She warmed up for the Championships by teaming up with Ons Jabeur in the doubles at Eastbourne last week and Wimbledon is widely considered her best chance of winning an elusive 24th Grand Slam.
Nadal is halfway to winning all four majors in 2022 after winning the Australian Open in January and a 14th French Open title earlier this month.
No man has achieved the feat since Ron Laver in 1969, with Novak Djokovic falling just short last year when he lost the US Open final to Daniil Medvedev.
Nadal's win at Roland Garros earlier this month took him to 22 Grand Slam singles titles - two clear of his great rivals Djokovic and Roger Federer.
Nadal won the most recent of his two Wimbledon titles in 2010, having captured his first with an epic triumph over Federer two years earlier.
There was a question mark over his durability for the two weeks at Wimbledon having played the entire French Open with his troublesome left foot anaesthetised.
The Spaniard, 36, has since undergone a course of radiofrequency stimulation, a treatment aimed at reducing nerve pain in his foot.
"I can walk normal most of the days, almost every single day," said Nadal, who faces Argentina's Francisco Cerundolo in his opening match.
"When I wake up, I don't have this pain that I was having for the last year and a half."
Swiatek's last match was a comprehensive victory against Coco Gauff in the French Open final - her 35th consecutive win.
Wimbledon will test the Polish top seed's ability to keep the run going. Reaching the fourth round last year was her best performance, even though she was junior champion in 2018.
"Grass is always tricky," said the 21-year-old. "I actually like the part that I have no expectations there. It's something kind of refreshing."
