Nadal won a record 21st major title at the Australian Open two weeks ago, surpassing rivals Novak Djokovic and Roger Federer.
The 35-year-old achieved it in just his second tournament back after recovering from a foot injury that ended his 2021 season to underline what a fierce competitor he is.
Nadal will once again be the favourite to win another major at the French Open in May, and his coach Moya, who is a former Grand Slam winner in his own right, says he has achieved a level few can match in sport.
"On the fingers of one hand you can count the athletes who in history have been able to experience situations similar to Rafa's and have been able to succeed," Moya told Punto de Break.
"Michael Jordan, Tiger Woods in his best moments, Novak Djokovic in tennis.
"That gene, that competitiveness, that way of managing to change outcomes is impressive."
Nadal is not the physical specimin he once was, which should be expected in his mid-30s and after the injuries he has endured, but Moya believes he has another weapon in his arsenal for which he rarely gets sufficient credit.
"I always say that Rafa is one of the most intelligent players on the court, one of those who reads games the best, the one who is most suited to having a Plan B, a Plan C," Moya said.
"I would tell you that he has the whole alphabet.
"If he sees that his opponent has a crack or the smallest gap through which he can enter, he reads it and gets through it.
"The final [against Daniil Medvedev in Australia] is a clear example, it starts badly but then it changes, little by little.
"That is the adrenaline that he has inside, to see that he can still fight with the best in the world."