PARIS — Roger Federer has undergone surgery to resolve a longstanding knee problem and said Thursday he would be out of action until after the French Open. The 20-times grand slam winner revealed on his Facebook account that he underwent surgery in Switzerland on Wednesday and would miss a string of tournaments including the May 24-June 7 French Open. "As a result, I will miss Dubai, Indian Wells, Bogota, Miami and the French Open," he said. The 38-year-old explained that he had intended to avoid surgery if possible but the knee problem refused to go away. "My right knee has been bothering me for a little while," said the world No. 3 who reached the Roland Garros semifinals last year. "I hoped it would go away, but after an examination and discussion with my team, I decided to have arthroscopic surgery in Switzerland yesterday." "After the surgery the doctors confirmed that it was the right thing to have done and are very confident of a full recovery. "I can"t wait to be back playing again soon, see you on grass!" Federer, who was to have competed for his ninth title in Dubai, has withdrawn from the Dubai Tennis Championships, organizers said. “We are very disappointed that Roger Federer, our defending champion, has been forced to withdraw from the Dubai Duty Free Tennis Championships this year,” said Colm McLoughlin, executive vice chairman and CEO of Dubai Duty Free. “His victory here last year, the 100th title of his career, was a significant milestone, and he went on to enjoy another outstanding season. We wish him well in his recovery and look forward to not only watching his progress during the rest of the season but welcoming him back to Dubai in 2021.” Tournament Director Salah Tahlak added, “We wish Roger Federer the very best, and despite this news, we still have a fantastic field including world No. 1 and Wimbledon and Australian Open Champion Novak Djokovic and last year’s finalist Stefanos Tsitsipas as well as Gael Monfils to name a few.” — Agencies