"2017 (Australian Open was) a special situation. Both (Federer and I) came back from a very long time without playing tennis. Nobody expected that, and it happened... That was big," ATP quoted Nadal, as saying.
"But today is a different story. We are back to the top positions, fighting for things again. It always has been a big challenge to face Roger all around the world, on the different surfaces (and in) different scenarios. 2017 (final) here is one of the matches that is going to stay in our minds," he added.
Talking about his preparations ahead of his opening match of the 2019 Australian open, Nadal asserted that there is always a scope for improvement and that he is pretty confident of his game.
"There are always things to improve. The serve was always a thing that I tried to improve, and I think I did. Maybe it was the time to try to make one more step. That's what we are trying. I am happy with it... I didn't compete with this new serve, so let's see how it works. I am confident it's going to work well," he said.
When asked for his views on Andy Murray's sudden retirement announcement, the 17 times Grand Slam winner said that it is "bad news". Wishing him good luck for future, Nadal said that the tennis world is surely going to miss him.
"Of course it is very bad news. When somebody like him (who has) achieved almost everything in his tennis career, is suffering like he (has been) doing for such a long time already and you feel that you are not competitive for the thing that really makes you wake up every morning and go on court with the passion to practice, to improve, and with a goal, then it is so difficult," he said.
"(Murray) will be a very important loss for us, for the world of tennis, for the Tour, for the fans, even for rivals. He has been part of a great rivalry between the best players for a long time and a great competitor... So all the best for him. We will miss him," he added.
Nadal is slated to play his first match of the 2019 Australian Open against James Duckworth of Australia on January 13.