Former Barcelona coach Terry Venables believes Manchester United midfielder Park Ji-sung should man-mark Lionel Messi tonight.
In his column for The Sun, Venables wrote: "Football is never a one-man game but to stop and beat Barcelona you have to stop and beat Messi.
"Prevent the Argentina maestro from playing and there is a fair chance you will stop Barca from playing.
"Not many teams have managed it in recent seasons but it can be done - as, dare I say, Jose Mourinho showed this season.
"Now the Special One and his Real Madrid players have not had much joy against their rivals this season. Thrashed 5-0 in La Liga at the Nou Camp and dumped out of the Champions League semi-finals, it is safe to say the Catalans have held the upper hand in El Clasico.
"However, Real's 1-0 victory over them in the Copa del Rey final should give United hope.
"That night, Pepe man-marked Messi out of the game and showed the greatest player on the planet can be stopped if you stick to him like glue.
"United have to do the same. One of their central midfield pair has to keep tabs on Messi.
"In the absence of Fergie's best man-marker Darren Fletcher, it is widely expected Giggs and Carrick will fill the places in the middle.
"But I do not know if either have the legs, concentration or determination to stick with Messi, so why not pull Park inside and revert Giggs to the left?
"It is the perfect solution. Park has never let United down."