Roger Federer will not play again until 2021 due to complications in his recovery from a knee injury. (More Tennis News)
The Swiss star was expected to be sidelined for four months after undergoing an operation back in February, his initial plan to return in time for the grass-court season.
With Wimbledon having been cancelled and the ATP Tour suspended due to the coronavirus pandemic, it was anticipated the 20-time grand slam singles champion could compete at the US Open in August.
However, Federer says a setback in his rehabilitation means he required a further arthroscopic procedure, and he intends to give his body as long as possible to recover.
In a Twitter post, the 38-year-old wrote: "A few weeks ago, having experienced a setback during my initial rehabilitation, I had to have an additional quick arthroscopic procedure on my right knee.
"Now, much like I did leading up to the 2017 season, I plan to take the necessary time to be 100 per cent ready to play at my highest level.
"I will be missing my fans and the tour dearly but, I will look forward to seeing everyone back on tour at the start of 2021."
In February 2016, Federer suffered a torn meniscus while running a bath for his children and then pulled out of the French Open due to a back problem.
He chose to skip the rest of the season after losing to Milos Raonic in the Wimbledon semi-finals, saying: "The doctors advised that if I want to play on the ATP World Tour injury free for another few years, as I intend to do, I must give both my knee and body the proper time to fully recover."
Federer enjoyed a spectacular comeback in 2017, winning seven titles including the Australian Open and Wimbledon, marking his most successful season for over a decade.
