Roland Garros royalty Chris Evert believes Rafael Nadal is 'weary' and says he could retire as early as next year.
Evert is perhaps the only player in tennis history to have a comparable record on clay to Nadal, who is chasing a 14th Roland Garros title this year.
He has made it into the quarter-final despite battling a foot injury, but he was taken to a rare fifth set on clay by 21 year old Felix Auger-Aliassime on Sunday.
After that match Nadal gave his views on Court Philippe-Chatrier, but Evert felt like something was a little off with the Spaniard.
Asked about Nadal's demeanour after his win over Felix Auger-Aliassime, Evert told Eurosport: "He is sounding weary.
"There is so much more that comes with being a professional tennis player than playing a match, but he sounded tired.
"The respect I have for him because he is 35 years old and he can keep getting psyched up every single day for these matches.
"I started burning out in my early 30s. When I woke up in the morning I didn't have anything in me, so I don't know where he gets this passion and fire in his belly from.
"I am sure with the injury, I don't want to say he is falling apart, but you get a little more affected by the playing and training.
"It is going to happen, whether it is next year, two years, three years. I would not give him more than two or three years to play tennis."
Nadal is set for a blockbuster quarter-final clash with Noval Djokovic on Tuesday.