<a href="https://www.thenationalnews.com/tags/roger-federer/" target="_blank">Roger Federer</a> says he faces “many months” in recovery as he prepares to undergo further knee surgery in the hope of prolonging his illustrious career. The Swiss, 40, has opted to undergo surgery on his troublesome knee that saw him miss out on the <a href="https://www.thenationalnews.com/sport/olympics/" target="_blank">Tokyo Olympics</a> to give himself “a glimmer of hope” of returning to competition. “I’ll be on crutches for many weeks and also out of the game for many months,” he said in a video on Instagram on Sunday evening. Federer, who has not played since losing in the quarter-finals of <a href="https://www.thenationalnews.com/tags/wimbledon/" target="_blank">Wimbledon</a>, will miss the final Grand Slam of the season at the US Open which gets underway on August 30. He had two knee surgeries in 2020 which resulted in more than a year of rehabilitation, returning to action in March - 13 months after his <a href="https://www.thenationalnews.com/tags/australian-open/" target="_blank">Australian Open</a> semi-final exit last year. He withdrew from the <a href="https://www.thenationalnews.com/tags/french-open/" target="_blank">French Open</a> in June after winning his third-round match to save himself for the grasscourt season and a bid to win a record-extending ninth Wimbledon title. “I just wanted to give you a bit of an update about what’s been going on since Wimbledon, as you can imagine it’s not been simple," Federer said. “I’ve been doing a lot of checks with the doctors as well on my knee, getting all the information as I hurt myself further during the grass court season in Wimbledon and it’s just not the way to go forward. “Unfortunately for the medium to long term to feel better I will need surgery so I decided to do it.” The news casts further doubt over whether Federer, the former world No 1 with a joint record 20 Grand Slam titles with Rafael Nadal and Novak Djokovic, can return to compete on the same level as his great rivals. He added: “It’s going to be difficult of course in some ways, but at the same time I know it’s the right thing to do because I want to be healthy, I want to be running around later as well again and I want to give myself a glimmer of hope to return to the tour in some shape or form. “I am realistic. Don’t get me wrong, I know how difficult it is at this age to do another surgery and try it. I want to be healthy, I will go through the rehab process I think also with a goal, while I’m still active, which I think is going to help me during this long period of time." Towards the end of his 97-second video, Federer thanked his fans for their support. "You guys are always incredible, you always think of me," Federer said. "Some of you suffer with me, some of you just wish me the best and want to see me back on court or see me smile. I am doing OK so I appreciate that. "And I’ll update you as I move along with my rehab. I wish you all the best and I’ll check in with you soon."