Third seed Aryna Sabalenka pulled out of Wimbledon shortly before her opening match on Monday due to a shoulder injury, organisers said, leaving the women's draw short of a leading contender for the title.
The Belarusian, who was set to face American Emina Bektas, was replaced in the draw by Russian lucky loser Erika Andreeva.
"I tried everything to get myself ready but unfortunately my shoulder is not cooperating," Sabalenka said on Instagram.
"I pushed myself to the limit in practice today to try my best, but my team explained that playing would only make things much worse," she added.
"This tournament means so much to me and I promise I'll be back stronger than ever next year."
Sabalenka, who suffered a lower back injury this year and struggled with illness at the French Open during her quarter-final loss to 17-year-old Mirra Andreeva, sustained the issue during last month's Berlin Open.
The Australian Open champion said on Saturday that she was still not 100 per cent heading into the year's third Grand Slam.
Since claiming her maiden Grand Slam title at the Australian Open in 2023, the 26-year-old Sabalenka has established herself as one of the most consistent players in major tournaments.
She reached the semi-finals at Roland Garros and Wimbledon last year, as well as the US Open final, and started 2024 by defending her Melbourne crown.
Russian 22nd seed Ekaterina Alexandrova also pulled out of the tournament due to illness ahead of her opening-round match with Emma Raducanu on Monday.
The 29-year-old, whose best performance at the All England Club came last year when she reached the fourth round, has been replaced by lucky loser Renata Zarazua of Mexico.
British hope Raducanu, 21, missed Wimbledon last year following surgery to her hands and ankle. The 2021 US Open champion has never advanced beyond the fourth round of her home Grand Slam.