Serena Williams withdrew from the French Open with an Achilles tendon injury on Wednesday shortly before she was supposed to face Tsvetana Pironkova in the second round on Wednesday.
The 39-year-old American, a three-time former champion at Roland Garros, was striving to claim a record-equalling 24th Grand Slam title.
"Struggling to walk," Williams told a news conference. "I felt like I needed to walk with a limp."
Williams had suffered the problem during her semi-final loss to Victoria Azarenka in the US Open and said ahead of her Roland Garros campaign that she was not at 100 per cent physically but had recovered sufficiently to play.
She spoke again of the injury after her first-round win over fellow American Kristie Ahn and apparently aggravated it while practising for her second-round match.
"An Achilles injury is not one you want to play with as it can get worse," she said.
Williams said she was yet to decide whether she would play again this season, saying she needed two weeks of complete rest, but said she still wanted to continue her career.
"I love playing tennis. I love competing. It's my job and I'm pretty good at it still... I'm so close to some things and I feel like I'm almost there... that's what keeps me going."
Williams also pulled out of the French Open in 2018 before a last-16 clash with Maria Sharapova.
Carlos Alcaraz will miss the Madrid Open for the second consecutive year after withdrawing on Friday with a wrist injury, dealing another blow to the world number two's clay court preparations ahead of his French Open title defence.
Novak Djokovic is still working through the injury problems that forced him to miss recent tournaments in Miami and Monte Carlo and said on Friday that he will not feature at next week's Madrid Open, one of the last stops before the French Open.
Mumbai Indians head coach Mahela Jayawardene has defended Jasprit Bumrah after the struggling pace spearhead went a fifth Indian Premier League match without a wicket in Thursday's seven-wicket defeat by Punjab Kings.
Iranian women's football players Fatemeh Pasandideh and Atefeh Ramezanisadeh thanked the Australian government on Friday for offering a "safe haven" and said they wished to resume their sporting careers after rebuilding their lives.
Ollie Watkins still has hope of making England's World Cup squad despite being dropped for last month's friendlies against Uruguay and Japan, with the Aston Villa forward saying all he can do in the last few weeks of the season is score goals.
Dubai Police, in collaboration with the UAE Ministry of Interior, have arrested an Irish fugitive accused of involvement in an organised criminal group linked to international crimes in his home country.
UAE President His Highness Sheikh Mohamed bin Zayed Al Nahyan has met with His Highness Sheikh Hamad bin Mohammed Al Sharqi, Supreme Council Member and Ruler of Fujairah, to discuss national priorities and the country’s continued development.