"I think he's a very complete player because he can play on all of the surfaces very good, and that's an advantage," said Nadal. "He started better than possible, so he's in a very good position.
"What he's doing well is he's playing with confidence. His level probably is not much higher than [it was] three years ago or two years ago or one year ago. I always saw him as fantastic player. His potential always was very, very high. Everybody knows how good is him, and he can do what he's doing now.
"My relationship with him always was fantastic. We are close. I think he's a funny guy."
Despite losing to Djokovic in the BNP Paribas Open final at Indian Wells on Sunday, Nadal feels that he can improve at Crandon Park, the venue of the ATP World Tour Masters 1000 tournament in Miami.
Nadal has a 21-7 Miami tournament record, which includes two runner-up finishes in 2005 (l. to Federer) and 2008 (l. to Davydenko).
"[I can improve] a lot of things. I think during the [Indian Wells] tournament I didn't play really good. It wasn't a good level for me. Semi-finals and final I improved my level of tennis, but during the final my serve worked terribly.
"So that's the first thing. I have to serve better if I want to have chances to compete against all the players. And from the baseline, seriously, I think I finished the tournament playing much better than the beginning of the tournament. So that's always a very positive thing."
With 18 ATP World Tour Masters 1000 trophies on his mantelpiece in Mallorca, Nadal has won at six different elite tournaments over the past six years. "I play every tournament with the same motivation," he said.
"[It] is impossible [to] win in every place. I just accept the challenge and try to play my best tennis. That's [the] only way to win the tournament where all the best players of the world are playing.
"I love the competition. Tennis is my sport."
Nadal plays Japan's Kei Nishikori in the Sony Ericsson Open second round.