Novak Djokovic believes that he needs to be at his best to defeat Roger Federer in the final of the BNP Paribas Open.
The world number two got the better of John Isner in the semi-finals at Indian Wells on Saturday, while his Swiss opponent for Sunday defeated Alexandr Dolgopolov.
Djokovic and Federer last faced each other in the semi-finals of the Dubai Tennis Championships in February, which the Serb lost in three sets.
"He played great in Dubai," ATP World Tour's official website quotes Djokovic as saying. "We had a tough, interesting match in semi-finals.
"Whenever we play each other, it's always a huge challenge for both of us, and very few points can decide the winner. I do not expect anything less tomorrow.
"I just hope for myself that I will be able to perform on a high level, because I'm going to need to do that in order to get a chance to win against him."
Federer is currently ranked eighth in the world.
