Roger Federer will be one player who will not be returning to action if it does return in 2020 as he is set to miss the rest of the year after a second knee operation.

Federer had the initial surgery in February; which worked out well of sorts due to Coronavirus suspending the season; but he has now said he suffered a "setback" with his rehabilitation.

This means a second arthroscopic surgery on his right knee has been completed; 2021 has been earmarked for his return.

"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," Federer said on Twitter on Wednesday.

"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."

"I will look forward to seeing everyone back on tour at the start of the 2021 season."

Federer has not played since losing to Novak Djokovic in the Australian Open semi-finals in January; having the surgery soon after.

Similarly in 2016, he missed the majority of the season with a knee injury; but returned the following year to win the Australian Open and Wimbledon.

But this time around, he will be 40 when he returns with his career more in its twilight than last time meaning an interesting complexion when he does.

https://twitter.com/rogerfederer/status/1270605149526986752?s=20