Madrid is still having copa del rey. Even though madrid was losing in aggregate against barcelona and it seems possible for madrid to beat barcelona in camp nou. This gonna be a huge challenge for real madrid how to beat barcelona in the next el classico.
As far as i know that if xavi is always using defensive strategy against real madrid. Madrid shall do the same thing like that. Even though the game will be running passive but that will force barcelona to play offensive too.
Madrid shall have learned from what already happened in the previous match against barcelona.
You are sure they will play defense. No, I think it's wrong. They can always have the ball in every game. That's their best game. In the first game, even Real Madrid had a great difficulty grabbing the ball. Of course Xavi will play that strategy. Real Madrid's chances certainly come from Barcelona's mistakes. Usually they will make a quick counterattack to make a goal. Logically, Real Madrid must be struggling even though opportunities are always open.
I don't even think if i'm wrong. Ancelotti was also feeling the same like me. He has even stated at the end of first leg of copa del rey against barcelona.
Ancelotti claimed it was 'strange' to see Barcelona play so defensively in the Bernabeu
https://www.dailymail.co.uk/sport/football/article-11815691/Carlo-Ancelotti-takes-aim-Barcelona-strange-display-claims-didnt-deserve-win.html4-3-3 normally can be called as a formation that was focusing on attacking strategy but barcelona was playing the opposite. The last match was a bit different caused by barcelona was playing the same formation but in attacking form, unlike the first leg of copa del rey against madrid.