"He hasn't won everything" says Toni Nadal about Rafael Nadal and his motivation to continue
The decision was taken in order to prologue his career as Nadal himself put it and the reason why Nadal wants to continue playing a few more years is rather simple. The Spaniard has always been a very hard worker never quite satisfied with what he achieved and he achieved many great things. His uncle and former coach Toni Nadal spoke about what keeps Nadal going after all these years:
“I‘ve been asked many times how to motivate a guy who has won everything. First of all, Rafael has not won everything. In fact, he has gained absolutely nothing from what is to come."
While Nadal might not have won everything, his deep desire to always do his best is what keeps his passion for tennis going. Even now, after yet another injury Nadal is determined to come back stronger and anybody would be mad to doubt him.
Nadal further said:
"If a guy who is lucky in life and has challenges ahead of him is unmotivated, then he is ungrateful. I believe that one has to be motivated in life.”
As you can see motivation is something deeply instilled into the core personality of Nadal and that will never change. It's something his uncle taught him very early in his age. Challenges are privileges and being unmotivated is being ungrateful at the opportunity that presents itself.