Rafael Nadal, world tennis champion and firm believer in pre-sports rituals, was forced to retire from the Australian Open on Tuesday after suffering an injury to his inner hip. Grimacing in pain, Nadal announced in the final set of the quarter-final match against Croatian powerhouse Marin Cilic that he was retiring from the tournament. Medical exams revealed that his injury was a strain to the iliopsoas muscle, located on the inner edge of his hip.

The Grade 1 injury is not career-threatening — Nadal is expected to return to the hard court in Mexico on February 26 — but it will take him out of the Australian Open altogether. Strain to the hip flexor, which involves the iliopsoas muscle, is an increasingly common tennis injury, and it can be quite painful. Mild over-stretching or tears in the iliopsoas muscle — actually two muscles, the psoas plus the iliacus muscle — are located in the front of the body, around the crotch, particularly causing pain to the groin.

rafael nadal hip strain
The iliopsoas muscle, located in the pelvis, causes pain in the groin and hip.

In professional tennis, hip injury is becoming an increasingly common problem because of the changing nature of the game, and players and critics alike have raised concerns about the currently preferred style of play putting more stress on the hips. Unlike the serve and volley style preferred in the past, the “power-baseline” strategy involves players spending most of their time at the back of the court, engaged in long rallies meant to break down their opponent’s defense. Relying on the repetition of long, powerful strokes for extended periods of time, the power baseline style is much more taxing on the body.

In a 2017 interview with Vice Sports, Todd Ellenbecker, vice president of medical services for the ATP World Tour, said that this generation of players is seeing an uptick in injuries to the hip, which is partially due to the “the baseline game with repetitive side-to-side loading from the groundstrokes.”

Ellenbecker also mentioned that most musculoskeletal injuries are “overuse in nature — i.e., they occur over weeks and weeks of continued play” — and that continued research will be necessary to determine how the rate of such injuries is affected by factors such as court surface.

Rafael Nadal hip injury
Some experts have expressed concern about the increasing number of hip injuries in professional tennis.

Nadal has been plagued with injuries over the years — some have argued that he’s simply getting old — most recently suffering injuries to his back and wrist in 2014 and another wrist injury in 2016 that forced him out of Wimbledon. After he retired from the Australian Open on Tuesday, Nadal voiced his concerns about the number of injuries currently affecting leading players in professional tennis — Andy Murray, Novak Djokovic, Hyeon Chung, and Stan Wawrinka are among them — and blamed the organizers of the Australian Open for not taking their situations into account.

“Somebody who is running the tour should think a little bit about what’s going on,” he said. “Too many people are getting injured. I don’t know if they have to think a little bit about the health of the players.”

For Nadal, treatment over the next two weeks will include anti-inflammatory physiotherapy and time off the court, but if he’s already thinking about “life after tennis,” as he alluded to in his interview, he might want to consider a recent professional poker player’s appraisal of his potential: “The more decision-making you have to make in a sport, the more similar it is to poker,” said PokerStars Pro Fatima Moreira De Melo in an interview with Express Sport on Wednesday, referring to Nadal.