Federer drops out of Rio 2016, rest of ATP season

Roger Federer has dropped out of next month's Olympics and will not play again the rest of this season, he announced on his Facebook page Tuesday.

That includes the U.S. Open and the ATP Finals. Federer, who turns 35 in two weeks, had already dropped out of this week's Rogers Cup.

"I have made the very difficult decision to call an end to my 2016 season as I need more extensive rehabilitation following my knee surgery earlier this year," he said in the statement, also citing his regret he would not be participating in Rio.

"I'm extremely disappointed to announce that I will not be able to represent Switzerland at the Olympic Games," he said. "I am as motivated as ever and plan to put all my energy towards coming back strong, healthy, and in shape to play attacking tennis in 2017."

Federer also withdrew from the French Open earlier this year. He reached the semifinals of the Australian Open and Wimbledon.