1. Iker Casillas v Victor Valdes
Spain captain Iker Casillas' position as first-choice goalkeeper for Vicente del Bosque at the World Cup finals is not in doubt, but he has not looked so assured recently, making some uncharacteristic errors.
Barcelona's Victor Valdes won the 'Zamora' award for the best record in La Liga last year and tops the charts again going into the 'Clasico'.
Like Casillas, Valdes is an excellent shot-stopper and his distribution from the back is the starting point for Barca's suffocating possession game.
Spain midfielder Xavi makes Barcelona tick even if he doesn't necessarily dominate the headlines.
His slick link-up play is the very essence of Barca's style, and cutting the distribution lines from the diminutive playmaker is vital to breaking Barca's domination of the ball.
He's a stronger physical presence and conducts affairs from a deeper lying position, but is often the starting point for Real's swift counter-attacks.
They top the La Liga goalscoring charts with 24 and 26 respectively, but while Messi's goal-scoring feats are hailed around the world, Higuain's contribution at Real is under the microscope.
The 22-year-old's gutsy displays have helped Real perform many of their trademark comebacks, flourishing in broken play with his surging runs into the area.
It's hard to judge the commercial impact of the respective signings on their clubs, but on the field of play the towering Swedish striker has gone closer to repaying some of the investment than his flashy Portuguese rival so far.
Ibrahimovic scored the game's only goal when Real visited Barcelona in November while Ronaldo missed his best chance when denied in a one-on-one with Valdes.
