"I was not afraid at all. I did my calendar and I was clear in my mind that I would not do a different calendar to be No 1," Daily Express quoted Nadal, as saying.
The Spaniard, who holds the number one spot in ATP rankings, keeping Federer on second the position, also hinted that grabbing a top rank was not his primary approach.
"I did what I believed was best for my happiness, for my tennis career and for my results, that's all."
Nadal, 31, recently became the oldest man to secure the year-end number one spot in the ATP rankings for the fourth time.
The 16 time Grand Slam champion said, "The fact I am No 1 here is great. It is a great achievement, especially at my age, to finish the No 1 in the world at 31 and a half is something important to me. But that is all."
However, Nadal, the "the King of Clay" is struggling with an injury in the current time.