"How do we stop this guy?" was the headline in Marca after the Argentina forward hit four past Arsenal to send holders Barca through to the semi-finals 6-3 on aggregate. "Messi is the one who scares us", said As.
NEWS:Messi 4-1 Arsenal
"You have to take your hat off to him because he is a player who makes the difference," Real and Spain defender Sergio Ramos said on Real's website.
"Our weapons will be to stay focused and show the maximum possible respect to Barcelona."
Real top the standings on goal difference with eight matches remaining but after Saturday's clash the head-to-head record will separate the arch-rivals if they are still level on points.
Barca have the advantage after Pep Guardiola's team won 1-0 at the Nou Camp in November and defeat for Real would be a serious setback to their hopes of success in the only competition they remain alive in this season.
Under the Chilean, Real failed to make it into the last eight of the Champions League for a sixth straight season and suffered an embarrassing exit to third-tier Alcorcon in the King's Cup.
"Why Arbeloa? Because he already marked him in four previous games and he did it successfully," the paper wrote. "He has the necessary method, focus, acceleration and the speed."
"I only know one way to (stop him) and that is to appoint Diego Maradona coach of Barcelona," Relano wrote, referring to the current Argentina coach.
"But that's not possible between now and Saturday so we can all agree that the Clasico is to a very large degree in Messi's hands."
