Roger Federer revealed his shock and sadness following Andy Murray's emotional announcement that he is set to retire as he labelled the former world number one a "Hall of Famer" and "legend".
A debilitating hip injury has forced Murray into looming retirement, with the 31-year-old three-time grand slam champion eyeing a Wimbledon farewell if he can make it through the Australian Open.
Federer reacted to the news on the eve of the Australian Open in Melbourne, where the Swiss great said he saw signs of Murray's downfall during a charity event in Glasgow in November 2017.
"I think his body took the decision, unfortunately, in this case," two-time reigning Australian Open champion Federer told reporters on Sunday. "I think it must have been a very long couple of years for him now.
"I remember when I played with him in Glasgow, I know how not well he was. I couldn't believe he actually played. But it was for a good cause. He felt like he could do sort of the two and a half sets that we played.
"I guess everybody can understand where he comes from. At some point when you feel like you're never going to get back to 100 per cent, you've had the success that Andy has had, you can only understand the decision. I was disappointed and sad, a little bit shocked, to know now that we're going to lose him at some point. But we're going to lose everybody at some point. It's just now that it's definite.
"Of course, I hope that he can play a good Australian Open and he can keep playing beyond that, really finish the way he wants to at Wimbledon. That's what I hope for him. Of course, it hits us top guys hard because we know Andy very well. We like him. He doesn't have many enemies, to be quite honest. He's a good guy, Hall of Famer, legend. He won everything he wanted to win. Anybody would substitute their career with his. He's a great guy.
"It's a tough one, but one down the road he can look back on and be incredibly proud of everything he has achieved."
Murray's retirement plan prompted questions about the future of 20-time major winner and 37-year-old icon Federer.
Federer, who has dealt with his own injury concerns having been struck down by back and knee ailments prior to his renaissance in 2017, told CNN: "I hope it doesn't end with an injury.
"I'd like to go out on my terms. I don't have the fairytale ending in my head saying there has to be another title somewhere, and then I have to announce it big and say, that was it, by the way, guys. I don't have to have it that way."
Could Wimbledon – the scene for eight of Federer's 20 slams – be where the world number three eventually calls time on his illustrious career? "I have a lot of places that are very special to me, thankfully. I've been very fortunate. But yeah, sure, like a Wimbledon stands out as maybe a place, but there are actually also many others.
"I've been thinking about it, like where is that place? But I think it will all come down to, is it the body, is it the family, is it the mind, is it one morning when I wake up, how does it happen?
"And then maybe that day that it happens, maybe that is the end, or maybe I say I can maybe get a few more tournaments left in me, I don't know."