Swiss tennis maestro Roger Federer has withdrawn from Tokyo Olympics owing to his knee injury during the grasscourt season. Federer announced the news on Twitter saying that he is "greatly disappointed" on missing out on an opportunity to represent Switzerland. "During the grass court season, I unfortunately experienced a setback with my knee, and have accepted that I must withdraw from the Tokyo Olympic Games. I am greatly disappointed, as it has been an honor and highlight of my career each time I have represented Switzerland," Federer tweeted. pic.twitter.com/ngIlD6MYew — Roger Federer (@rogerfederer) July 13, 2021 The 39-year-old has begun rehabilitation and hopes to return to action later this summer. "I have already begun rehabilitation in the hopes of returning to the tour later this summer. I wish the entire Swiss team the best of luck and I will be rooting hard from afar. As always, Hopp Schwiz!" he added. Earlier, Federer was knocked out of Wimbledon by Poland's Hubert Hurkacz in the quarter-finals. Hurkacz beat the veteran in straight sets to reach the semi-final. In the first round of the tournament, Federer survived a scare after France's Adrian Mannarino retired due to injury. In 2020, Federer had two knee surgeries. He even had to withdraw from French Open despite winning three matches to save himself for Wimbledon. “After discussions with my team, I’ve decided I will need to pull out of the French Open today. After two knee surgeries and over a year of rehabilitation it’s important that I listen to my body and make sure I don’t push myself too quickly on my road to recovery. I am thrilled to have gotten 3 matches under my belt. There is no greater feeling than being back on court,” he tweeted then.