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The El Clasico rivalry between Barcelona and Real Madrid is one of the fiercest in football. The campaign for Catalan sovereignty centres around the Blaugrana, adding a heavy political weight to the battle between Spain's top sides.
Transfers between the clubs are rare, with the likes of Samuel Eto'o and Ronaldo (not Cristiano) using a third club as a buffer before turning out for their former rivals.
However, Barca are set to lose their goalkeeper Victor Valdes at the end of the season. Valdes has grown tired of the pressure surrounding his role at Barcelona after 11 years between the sticks at Camp Nou. The search for a replacement is well and truly on, with Real Madrid captain Iker Casillas among the rumoured candidates.
Having been dropped by Jose Mourinho following a behind-the-scenes bust-up, Casillas is tired of the circus surrounding the Bernebau, and the perceived lack of support from club president Florentino Perez. Joining Barcelona would be the perfect rebuttal from a world-class 'keeper who currently feels undervalued.
Xavi has said that this deal won't go through, so we should probably expect fireworks in Spain this summer.