The players last met in the semi-finals in Miami earlier this year with Nadal winning in straight sets.

Both players won their quarter-finals in straight sets on Friday with Nadal beating Michael Llodra of France 6-2 6-2 while Federer saw off the challenge of fifth seed Robin Soderling of Sweden 7-6(7-2) 6-4.

Nadal had an extra day of rest after Juan Martin Del Potro pulled out of their third round match on Thursday with a hip injury and the world number one looked fresh and was in impressive form against Frenchmen Llodra.

Nadal wrapped up the match in one hour and 15 minutes and was pleased with his performance: "I didn't think I would win like that," said Nadal after the match.

"He's got a strong serve and dangerous volley so it's hard to pass him. But in the first set he committed errors."

"Winning that first set gave me a lot of confidence."
Roger Federer had a tougher time against Soderling, needing one hour and 42 minutes to subdue the Swede and progress to meet Nadal.

The former world number one managed to break the Soderling serve once throughout the match but it was enough for the Swiss and enabled him to then serve out the match in the next game to win 7-6(7-2) 6-4.

Looking ahead to today's match Federer was aware of the challenge: "I think this is a match that many fans and media want to see, especially here in his home country," said Federer. "It's obviously special and nice. On clay it's obviously his territory a bit more, but I’ve enjoyed my time with Rafa on the court, even though I have a lot more time left on the court with more victories."

Today's other semi-final in Madrid will feature Serbian Novak Djokovic and Brazilian Thomaz Belluci after Djokovic overcame the challenge of Spaniard David Ferrer in three sets 6-4 4-6 6-3 and Belluci continued his run, following up his victory over Andy Murray in the third round with a win against seventh seed Tomas Berdych 7-6(7-2) 6-3.