WIMBLEDON, England — Rafael Nadal withdrew from Wimbledon because of a torn abdominal muscle on Thursday, a day before he was supposed to play Nick Kyrgios in the semifinals.

It is the first time since 1931 that a man pulled out of the oldest Grand Slam tournament before a semifinal or final.

“I made my decision because I believe that I can’t win two matches under these circumstances,” Nadal said at a news conference at the All England Club. “I can’t serve. It’s not only that I can’t serve at the right speed, it’s that I can’t do the normal movement to serve.”

The 22-time major champion sighed occasionally while answering questions in English, then Spanish, for more than 20 minutes total. He twice described himself as “very sad.”

Nadal said trying to continue to compete could make the injury worse.

The only other time in his career that Nadal gave a walkover to an opponent by pulling out of a Grand Slam tournament prior to a match came at the 2016 French Open, when he withdrew before the third round because of an injured left wrist.

The 40th-ranked Kyrgios, a 27-year-old from Australia, advanced to his first title match at a major tournament and becomes the first unseeded men’s finalist at Wimbledon since Mark Philippoussis, who lost to Roger Federer in 2003.

“I hope your recovery goes well and we all hope to see you healthy soon,” Kyrgios wrote in an Instagram post addressed to Nadal.

Kyrgios will meet either three-time defending champion and No. 1 seed Novak Djokovic or No. 9 Cam Norrie of Britain for the championship on Sunday; their semifinal will be played Friday.

The second-seeded Nadal, a 36-year-old from Spain, is 19-0 in Grand Slam action in 2022, including trophies at the Australian Open in January and the French Open in June. That put him halfway to a calendar-year Grand Slam for the first time in his career.

Nadal has been bothered by a stomach muscle for about a week, and the pain became nearly unbearable in the first set of his 4-hour, 21-minute victory via fifth-set tiebreaker against Taylor Fritz in the quarterfinals on Wednesday.

After that match, Nadal said he had considered stopping before it was over — and could not be certain whether he would feel well enough to play again Friday.

He wore two strips of athletic tape on his lower stomach and took a medical timeout to take painkilling pills; his father and sister motioned from the stands for him to quit.

On Thursday’s off day, Nadal went to the All England Club for a light practice session. He was signed up on the official schedule to train on one of the competition courts but did not show up there, instead opting for practice courts to which fans don’t have access.

Mostly content to hit forehands and backhands, Nadal did attempt a few serves — the part of his game that revealed the most obvious inability to play with full force and, he said, caused the most discomfort against Fritz. Those practice serves Thursday were generally tapped in, by Nadal’s standards, not with any of the body-torqueing effort he usually uses.

“I was thinking during the whole day about the decision to make,” Nadal said.

It’s not far from what went on with Nadal at Roland Garros, where he took repeated injections to numb the chronic pain in his left foot and insisted he had no idea when he might reach the point of not being able to take the court.

He tried a new treatment after leaving Paris, and that worked well enough, Nadal said, to allow him to walk without limping.

His level of play through five matches on Wimbledon’s grass was such that he thought he had a chance to win a third title at the tournament, after those in 2008 and 2010.

The injury changed things, of course.

“I don’t want to go out there, not be competitive enough to play at the level that I need to play to achieve my goal,” he said.

Nadal said he thought he might be sidelined for about a month or so. The year’s last Grand Slam tournament, the U.S. Open, starts Aug. 29.