The excitement is building for the showdown between Roger Federer and Rafael Nadal, and the players themselves are relishing the last-16 clash at the BNP Paribas Open.

Federer overcame Nadal in a thrilling Australian Open final in January, and the two greats will treat fans again in one of tennis' most celebrated rivalries at Indian Wells on Wednesday.

A quarter-final berth is up for grabs as 18-time grand-slam winner Federer and Nadal do battle for the 36th time, with the latter and 14-time major champion leading their head-to-head 23-12.

After edging Steve Johnson 7-6 (7-3) 7-6 (7-4) on Tuesday, four-time Indian Wells champion Federer told reporters: "I'm very excited. That's why I came here, play against guys like Rafa. Now we have it.

"Australia helps me a little bit, but at the end of the day, I'm still in the comeback.

"I try to see it really as another opportunity to build upon something for the rest of the season. So regardless of Australia, winning or losing, I'm going to try to go out there and try to play free again.

"I think it's really important. I feel like if I move well, I will definitely have a chance against Rafa."

Nadal emerged victorious in his fourth-round clash earlier on Tuesday, having defeated fellow Spaniard Fernando Verdasco 6-3 7-5.

Without a win against Federer since the Australian Open in 2014 - a run of back-to-back defeats - Nadal knows he has his work cut out in the earliest meeting between the pair since the third round of the Miami Open in 2004.

"Federer has the talent to do very difficult things that look easy. He's able to take the ball very early. Serve and first shot, he creates a lot of winners with that, the two first shots," Nadal said.

"And then he's able to take the ball always from inside, and he's very quick going to the net. If you play a short ball, then you know that he’s going to go inside and going to hit a winner, going to play a shot [to your] forehand or backhand, goes to the net, and you are going to be in big trouble."