Olympic gold medalist Alexander Zverev feels Roger Federer, 41, will have a harder time making a comeback than Rafael Nadal, 35, because of their age difference.
The World No. 3 discussed the comeback of the two legends with Boris Becker in the Das Gelbe vom Ball podcast on Eurosport Germany on Friday.
Claiming to be a big Roger Federer fan, the ATP Finals champion pointed out that the Swiss had proved people wrong many times in the past with his age-defying feats. However, Zverev reckons the game has now become faster, making it difficult for Federer to make a glorious return after knee surgery.
"With Rafa it will be a bit easier than with Roger since Rafa hasn't been away that long and he is five years younger than Roger," said Zverev. "Roger has already achieved many things where we said: That's not possible. That's why I wouldn't write him off. It won't be easy, but tennis changes and becomes faster. At some point, this is no longer easy.
"There is no bigger Roger fan than me, but I don't know how easy it is to make another comeback at almost 41 years after a knee surgery," he added.
Roger Federer underwent a couple of knee surgeries last year following which he returned to action in March. The 40-year-old re-injured his knee during the grasscourt swing, which resulted in further surgery and another layoff for the Swiss.
Federer, whose ranking has dropped to 16, has admitted he will not rush back into action, although he is reportedly eyeing next year's Wimbledon Championships for a comeback.
Rafael Nadal, meanwhile, was sidelined for four months this year due to a foot injury. The 35-year-old returned to action at the Mubadala World Tennis Championship in Abu Dhabi earlier this month, where he lost both his matches.
The southpaw tested positive for COVID-19 upon his return to Spain, potentially jeopardizing his chances of participating in the Australian Open.
"I am the last one to say Roger Federer should stop but it has to be realistic" - Boris Becker
Echoing Zverev's sentiments, six-time Grand Slam champion Boris Becker said it's "unrealistic" to think Federer can recapture his best form when he returns to the tour.
"With Federer we all don't dare to say that he might not play any more, especially since it's unrealistic that you can return to the top of the world after such a long break and at this age," he said. "I am the last one to say Roger should stop but it has to be realistic."
Becker isn't overly optimistic about Rafael Nadal's chances either. According to the German, the four-set defeat to Novak Djokovic in the semifinals of Roland Garros this year has had a lasting effect on the Spaniard.
According to Becker, the World No. 6's positive COVID-19 test has further compounded his problems.
"With Rafa I see it a little bit differently," he said. "I think the semifinal match against Novak still gnaws at him a lot and after that there was a long break until now. He confirmed that he got COVID-19 and is now unsure whether he will play in Melbourne. So I see the end somewhere there as well. With Rafa, too, I hope he continues to play forever.
"But I think the two greats of tennis now have to think seriously about how long they can be called (active) tennis players," he cautioned.
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