Rafael Nadal's coach has revealed the Spanish superstar retains a “small hope” he will continue his career next year and return to Roland Garros. And former world No.1 Carlos Moya has insisted “the moment has not come” for the 22-time Grand Slam winner to retire.

After Nadal lost to Alex Zverev in the first round of the French Open, he said: “There’s a big percentage I won’t be back here, but I can’t say 100 per cent.”

His coach Moya has revealed Nadal had wanted at times to retire during his comeback - and could not play more than two sets when he returned to action in Barcelona.

But after showing the best form and fitness in his comeback in Paris, the 1998 French Open claimed the 14-time winner could have won the tournament if he had reached the quarter-finals. And Moya said he is not yet ready to accept that the Olympics will be the end of his career and he could return to the French Open net year.

“He said it himself,” said Moya. “It is not easy but he has a small hope. He does not know what is going to happen with his body, his level. But today, he does not want to close the door.”

Nadal gave a heavy hint he will not switch to grass and play Wimbledon before the Olympic tennis tournament returns to Roland Garros. “I don't think it's a positive idea right now,” he said. But Moya insisted: “We have not yet spoken about it.”

King of Clay Nadal had lost only three matches in 18 previous appearances at Roland Garros before Monday. Andy Moya claimed: “For me, Rafa, if he had reached the quarter-finals at Roland Garros, he would have remained a big favourite.

“That is what makes him different from the others. He would have won four consecutive matches, built up confidence and he would have tested himself physically. A player’s ultimate progression comes from competition.”

Speaking to L’Equipe, the Spaniard said Nadal and his team were still happy with the performance in the loss to Zverev after his battle to regain fitness from hip and abdominal injuries.

“I cannot say that it was not a defeat,” he said. “But his match here was the best since his return this season on the clay. But we knew that that could happen, we accept it and we can say that, at times, we saw the Rafa that everyone remembers. The atmosphere in the dressing room afterwards was good.

“We knew that he could lose to Zverev and the normal thing was to lose the match. But there are ways of losing. And in this defeat, Rafa showed himself to be competitive, he showed himself capable of playing at a good level, even if he did not take his chances.

“This match allowed him to see that with consistent play, without injuries, he could still play at a good level. To see that there are no longer physical limitations also means we can work better. There were days where we could do almost nothing. At Manacor, there were very short training sessions.”

Asked if he could have imagined Nadal playing so well even 10 days ago, Moya said: “Honestly not.” Nadal missed last year with a hip injury and suffered another hip problem in Australia in January. Then an abdominal injury forced him out of Indian Wells and Monte Carlo before his return to the tour in Barcelona.

“Physically we knew that he was not ready,” said Moya. “We decided to play the tournament to get back on tour but we said to him: ‘Please, don’t play a match of more than two hours’. That was the key for us. He had to win matches in two sets.

“The aim was Roland Garros and an injury at Barcelona would have put an end to everything. We knew that if he played more than two hours, there was a big risk that he would injure himself permanently.

“He accepted it. Against De Minaur, he lost the first set 6-5 and did not insist. There were a lot of times when he said: ‘I can’t anymore.’

“After Barclonea , he didn’t say that kind of thing anymore. It was hard but he wanted to carry on. He likes competition, he is a fighter. After a year and a half of suffering, he is today able to think only about tennis, to enjoy it and decide himself when he is going to retire. He has earned that right.”

Asked when Nadal will retire, Moya said: “It’s difficult. There have been times where he wanted to retire. When the moment comes, you know, you say: ‘Enough, it’s over’. But now, the moment has not come.”