Default Girl: Rafa has to be the favourite today. Home crowd advantage, leads on the head to head and most importantly, Djokovic is not across the net.

Ross McD: You have to back Nadal on clay to come through here, but Murray will make him work very, very hard for it.

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A couple of big kicking serves and a wasteful backhand from Nadal give Murray a swift 40-0 advantage and a perfect first game for the British number one is completed when Nadal crashes a backhand long.

Here we go then. Murray to serve first in the Spanish capital.

Here's Andy Murray's thoughts on the challenge facing him in Madrid this evening: "I'm aware it's going to be incredibly difficult. Playing against Nadal on clay in Spain is a big test. The crowd is incredibly pumped when he gets on the court. I have to be there mentally and play a smart match.

"You obviously need to play aggressive tennis but it's important not to go for too much. It's important that you have good tactics, trust your shots and hopefully play well. If I want to win, I'm going to have to play extremely well."

Service practice now. Mauresmo is there too, supporting her charge.

If injuries have made Nadal a lesser player, he has given little sign of it this week. The magician from Mallorca has been back to his imperious best on his favourite surface, failing to lose a set en route to the final of a tournament he has won five times.

But Murray is not playing badly himself. He has an 8-0 record on clay this year and ruthlessly dismantled last year's finalist Kei Nishikori in yesterday's semi-final.

Image source, @PatrickMcEnroe/Twitter

Former United States Davis Cup captain Patrick McEnroe, brother of three-time Wimbledon champion John, has let us all know his opinion on Twitter - what about you?

Can he do it? Can Murray conquer the king of clay? And more to the point, is there are harder challenge in sport than beating Nadal on his favourite surface?

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The players are out on court exchanging forehands in the late afternoon Madrid sunshine, with Nadal's uncle Toni looking on purposefully. A defeat would see Rafa slip outside the world's top five.

Russell Fuller
BBC tennis correspondent on Radio 5 live sports extra

"Murray should be full of confidence ahead of the final, as he is still unbeaten on clay this year. The extra week's preparation in Munich has done him the world of good, even if the wet weather there and the scheduling in Madrid have left him more than a little weary. But his opponent remains the master of the surface. Nadal has beaten Murray in all six of their meetings on clay, and there's a bounce in his step again: he's threatening to hit peak form just in time for Roland Garros."

Well, if Murray is our metaphorical bus, he has one almighty obstacle blocking his road to the expectant passengers at the next stop.

Rafael Nadal - the nine-time French Open champion and undisputed king of clay - lines up on the other side of the net.

Orders don't come much taller.

On Monday in Munich, Andy Murray ended a 10-year wait for his first clay-court title.

Six days later in Madrid, the British number one stands on the threshold of a second.

You know what they say about London buses...