"He is someone who simply never gets worn out". Then there's a resurgent Rafael Nadal, the likes of Cilic and Sasha Zverev.
"And I will continue to hope that the powers that be will find a way to capitalise on his success to create a lasting tennis legacy in Scotland and help to make us a fitter, healthier and more ambitious nation". "I don't have to have it that way", said Federer, who won three of his 20 major titles in the past two years.
But Dr John O'Donnell, who operated on the Scot's troublesome right hip, said: "I don't think it is impossible, but it will be very hard".
"I know what Denis did to Novak".
The early stages of the Australian Open have been dominated by the news of Murray's impending retirement.
"This year, again, we'll see what happens, but I'm very happy with the preparation thus far", Federer said Sunday in his pre-tourney presser.
Djokovic won his third US Open in September to put him on 14 Grand Slams - three behind Nadal and six behind Federer.
"It's a tough one, but one down the road he can look back on and be incredibly proud of everything he has achieved".More news: At least nine dead after snowstorm batters US Midwest, covers Washington
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Murray's final match could come in the first round in Melbourne against world number 23 Roberto Bautista Agut on Monday. I know that will be hard.
"I watched basically the entire match a couple years ago when he beat Novak here. It allowed me to believe in myself that I can actually win the biggest tournaments in the world, challenge the best players in the world".
"[It] will be a very important loss for us, for the world of tennis, for the tour, for the fans, even for the rivals that he has been part of a great rivalry between the best players for a long time, and a great competitor", Nadal said. I don't think there's any doubt about that. "That's always a good thought".
"The fact is that I just don't feel comfortable talking about these things, even in private. Or I can do it, but it's not fun or enjoyable doing it any more". "But is a little bit different because past year I had about 10, 15 matches before Melbourne, now I have only one, which I lost it".
"I feel like maybe more people want to take pictures".
Wozniacki revealed at the season-ending WTA Championships that she'd been diagnosed with rheumatoid arthritis, so she spent much of the off-season resting and recuperating and getting ready for 2019.
Another win at Melbourne Park would settle the argument once and for all, but Court said the American no longer had the fearlessness of youth on her side.
Federer did not concur with the widespread view - voiced since Murray's surprise announcement that he aimed to retire after Wimbledon, if not much sooner, due to his chronic hip problem - that the Scot had been unlucky in the timing of his career.