Nadal appointed Moya to be his new coach shortly before splitting with Toni Nadal early last year.
However, because the Spaniard is constantly pushing for ‘perfection’ he often comes to blows with Moya.
Nadal is top of the world rankings and gunning for his 17th Grand Slam title at the French Open this week.
And Moya has explained how desperate the 32-year-old is to continue improving – and that even causes contradicting views with his coach.
“He can keep improving every year and I tell him a few things and he is telling me things that he does not agree with,” Moya told ITV.
“But we try to reach an agreement of how to do things.
“I am not always right and there is a few things which we discuss.
“I am not always right with what I see from outside – but he is the one who is feeling things on the court and we try to sort out a few things.”
Nadal is gearing up to face Diego Schwartzman in the quarter-finals at Roland Garros this afternoon.
And Moya is confident he will be able to book his place in the last four.
“He is a perfectionist and he wants to do well. He wants to be perfect on the court,” Moya added.