Rafael Nadal has won 17 Grand Slam titles in his career though was forced to withdraw from the US Open semi-final against Juan Martin del Potro earlier this month.
That was down to a knee injury with Nadal suffering persistent problems in his joints throughout his career.
That’s not stopped the 32-year-old being hugely successful, having won the French Open this year and reached the semi-finals at both Wimbledon and Flushing Meadows.
But Moya, who was forced to retire in 2010 with a persistent foot injury, admits that Nadal’s body will be the ultimate factor in deciding when he retires and says that the Spaniard will call it quits when he can no longer compete at Grand Slams.
“Practically 90 per cent of withdrawals or more are related to physical problems,” Moya told El Pais.
“Very few people retire at 100 per cent physically and at a high level, so we are aware that this can happen. In fact, it happened to me.
“Precisely, we are trying to avoid Rafa having to go through a circumstance like that, which I went through, but it is not easy.
“The injuries come at any time and although at that moment you do not know it, sometimes they lead you to retreat.
“At the time it is what happened to me [in 2010, at 34 years old] and now I do not want it to happen to him.”
“The body is giving you signals and, above all, the head too.
“It is not a decision that is taken from one day to the next, much less.
“It’s been months of thinking and I think Rafa has not yet reached that state.
“The ranking also marks you a little that moment and I do not see Rafa fighting without being among the 10 or 15 best in the world.
“Out of respect for himself, his name and who he is, I think he should not become a player who fights to reach the quarterfinals of the tournaments.”