Rafael Nadal pulled out of next week's National Bank Open in Montreal, citing "a little discomfort" as the cause.
An abdominal strain forced Nadal, ranked No. 3 in the world, to withdraw from the semifinals at Wimbledon, where the Spaniard was scheduled to meet Australian Nick Kyrgios.
At Wimbledon, Nadal was seeking his 23rd Grand Slam title -- third this year following his wins at the Australian Open and French Open. He is 35-3 on the year, also winning in Melbourne and Acapulco.
Nadal, 36, didn't state in his social media announcement whether he believes he will be ready for the season's final major at the U.S. Open, which begins Aug. 29 in New York.
"I hope to play again in Montreal, a tournament that I love and that I have won five times in front of an audience that has always welcomed me with great affection," said Nadal, according to a Google translation of his notes posted to Twitter in Spanish. "I have no choice but to be prudent at this point and think about health."
On Thursday, Wimbledon champion Novak Djokovic withdrew from the Montreal event.
The Serbian star's withdrawal was a foregone conclusion, given his unvaccinated status. Anybody traveling into Canada must have at least two doses of the vaccination against COVID-19. Djokovic, 35, remains steadfast in his decision not to get the vaccine.
The ATP 1000 event in Montreal is a hardcourt tune-up for the U.S. Open, which Djokovic is also likely to miss barring an 11th-hour exemption. Current rules require non-U.S. citizens to show proof of being fully vaccinated before entering the country by air from a foreign nation.
--Field Level Media