It took Rafael Nadal a year to finally start working on his serve: Carlos Moya

Rafael Nadal's improvement on his serve since former French Open champion Carlos Moya took over as his coach in 2017 has been well-documented. Nadal's spruced up serve won him a couple of US Open titles among other things, but Moya has now revealed that the 19-time Grand Slam champion took an entire year to finally decide to work on the shot.

Speaking to noted tennis commentator Annabel Croft on the ATP Champions Tour Instagram live chat, Moya explained how Rafael Nadal took some time to get used to the new set-up. Parting ways with Uncle Toni - who had been his coach for 15 years - was not easy for the Spaniard.

Nadal was already low on confidence at that time, after his struggles on the court in 2015 and 2016. It took the Spanish southpaw some time to come to terms with the fact that his game needed a change, and after a year he finally decided that he could put it off no longer.

"He was humble enough to be aware of his weakness or face that he can improve," Moya said. "And that is the key. We had been telling him for one year that his serve has to be better but he was reluctant to change something. But then he was the one to say, ‘Okay, right now.’ Right after that moment it was the time for us to step in."

Rafael Nadal collected two US Open titles as well since the arrival of Moya

With Moya by his side, Rafael Nadal was able to summon the champion in him again. In a stellar 2017 season he made it to three Grand Slam finals, winning two of them - the French Open and the US Open.

The spectacular turnaround saw Rafael Nadal finishing the year as the No. 1 ranked player - something that looked unimaginable a year earlier.

The southpaw went on to add three more Majors to his illustrious resume over the next couple of years, and even now looks very hungry for more success.

It was all about patiently listening to the changes that Carlos Moya suggested, most of which were based on incorporating more aggression. But Moya emphasized that aggression did not mean merely hitting the ball with more power; it also involved clever court positioning.

"Being aggressive isn’t about hitting hard, it’s about positioning on court as well," Moya said. "Being aggressive is more about having it in his mind that he can play a step closer to the baseline."

Elaborating further on the changes in the serve, Moya mentioned how Nadal kept experimenting with his motion in the initial stages without settling on any fixed pattern. Once the realization dawned upon him that he had to stick to one method, it became easier for Rafael Nadal to embrace a complete transformation.

"He was very keen to change his serve after one year when I was with him," Moya revealed. "He was injured in his knee and he realized it was the moment to try. He tried it but we saw how he did not find a way to keep the same motion."

"He was changing the motion every 2-3 months and he realized he needed to change his serve in order to be a better player," Moya added. "We tried to change a couple of things and he was feeling comfortable since the first moment. I think it paid off."

The revamped serve took Rafael Nadal to the Australian Open final in a blistering start to the 2019 season. He went on to win two Majors later in the year - including the US Open, where the serve again played a big role.

My favorite drill with Rafael Nadal is 2 vs 1: Carlos Moya

Moya explaining to Rafael Nadal during a practice session

Moya also shed some light on the specifics of the training sessions with his champion ward. The sight of Rafael Nadal scampering all over the court is something every tennis fan is familiar with, and Moya said that they work on his alertness and speed by subjecting him to 2 vs 1 drills.

Rafael Nadal has to deal with two players on the opposite side of the net, which helps him to be ready for variations in speed and direction.

"I like to do 2 vs 1 drill for Rafa, where Rafa has to play two players," Moya said. "He is changing pace, changing directions. When you play tennis, it’s about changing directions to make the opponent run. His speed of the ball is very high so that we can do it from side to side.

"We do that everyday. With me and a hitting partner (being there), we don’t need a top professional player for it," he added.