Roger Federer to skip U.S. Open due to knee surgery

Swiss tennis star Roger Federer will miss the U.S. Open tournament later this month because of a knee surgery.

In an Instagram video on Sunday, Federer expressed his disappointment, but said it was the best decision for his career.

"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 also to return to the tour in some shape or form."

The 40-year-old tennis player has already had two recent knee surgeries, which took him out of the game for more than a year.

He still has hopes of beating the men's record for most Grand Slam title wins, although that won't happen this season.

In June, Federer withdrew from the French Open to save himself for the grass court season.

He reached the quarter-finals at Wimbledon, but lost in straight sets.

He then withdrew from the Tokyo Olympics.

Federer shares the men's record of 20 Grand Slam titles with Rafael Nadal and Novak Djokavic, who is currently number one in the world.