Federer, unable to play due to injury, was a part of the Wimbledon’s celebrations for the centenary of Centre Court in July
The 20-time Grand Slam champion is retiring from the game after this weekend’s Laver Cup in London.
The Swiss, 41, has not performed since Wimbledon 2021, after which he had a 3rd knee operation.
“The last three years have been tough to say the least,” he told BBC Breakfast.
“I knew I was on very thin ice for the last year ever since I played Wimbledon.
“I tried to come back but there was a limit to what I could do. And I stopped believing in it, to be honest.”
Federer said he had a scan a couple of months in the past and it was “not what I was hoping for”, including: “Very quickly we realised this was it.
“Then the question becomes: how do you announce and when do you announce? This is when it becomes reality. It was OK but stressful.”
In a large-ranging interview with Sally Nugent, Federer mentioned his emotional retirement statement, mirrored on his trophy-laden profession, regarded at what’s subsequent for him and supplied his reminiscences of the late Queen.
‘Writing those words was like rehab’
The eight-time Wimbledon champion introduced his retirement last Thursday in a statement on social media.
“It’s been an emotional few weeks to go through those words to try to get them right, that they reflect how I’m feeling and thanking all the people who have helped along the way,” he said.