"Dear Fans (sic), I hope you are staying safe and healthy. A few weeks ago, having experienced a setback during my initial rehabilitation, I had to have an additional quick atrhtroscopic 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% ready to play at my highest level.
Stay safe @rogerfederer! We all are devastated hearing the news and hope that you recover fast! Can wait to see you back on court! Always a legend Roger! pic.twitter.com/RCskcOS4HD
Wimbledon has since been cancelled due to the global Covid-19 crisis, while the Tokyo Games have been postponed to next year. Organisers of the French and US Opens are considering ways of staging their respective events.
The latest setback will not do anything to dispel the imminent retirement rumours that have dogged Federer since 2013.
Federer missed the Rio Games and much of the 2016 season due to injuries to his knee and back but returned the following year to complete his most successful season in a decade - including wins at the Australian Open and Wimbledon (his first Slam victories since 2012).
He is currently ranked No 4 in the world, after reaching only one Grand Slam final last year - losing in a five-set thriller to Novak Djokovic in the title-decider at Wimbledon.