Cesc Fabregas has compared Spain's Euro 2012 semi-final clash with Portugal to the El Clasico match.
The two nations will meet in Donetsk on Wednesday for a place in Sunday's final and the Barcelona midfielder is wary of the threat posed by their Iberian neighbours.
"Portugal is one of the strongest teams," said Fabregas. "They defend well and are lethal on the counter. They're similar to Real Madrid and we must be at the top of our game.
"You can liken and compare it to Real Madrid–Barcelona in terms of the respective styles of the teams, but there are different players and we also have players from many teams so it'll not be the same."
The other semi-final sees Italy take on Germany in Warsaw on Thursday.
