Casillas saved spot-kicks from Daniele de Rossi and Antonio di Natale at Vienna's Ernst Happel Stadium after a stalemate against Italy, setting up a repeat of Spain's first match of the finals.

Spain won 4-1 on that occasion but Casillas said: "We would be naive to think that because we defeated 4-1 we would get to the final easily."

He added: "We know they are a great team and have shown it against Sweden and Holland. The previous result is of no value, it is a new match."

Spain coach Luis Aragones feels Russia have a physical advantage due to a different schedule for their domestic season.

"It is the best moment for Russian football, because this is the moment of the season they are at their best," he said.

"The second half of matches is about speed and we are going to have it tough. We won 4-1 last time but it will be difficult because they have a really good team."

Aragones was confident of Casillas saving them when the match against Italy went to spot-kicks.

"I was sure he was going to stop penalties because he has a goalkeeper trainer that tells me they watch where the rivals take penalties. They were looking at DVDs and looking at these things," he said.

After Casillas' two saves it was left to Cesc Fabregas to tuck away the winning penalty. It was the first time they had beaten Italy in a competitive match since the 1920 Antwerp Olympics and also ended their run of penalty defeats on June 22, at the World Cups of 1986 and 2002 as well as Euro 96.