Real Madrid vs. Barcelona: 5 Key Battles to Watch in Copa Del Rey Semifinal

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With Real Madrid due to face Barcelona in the Copa del Rey, football fans across the globe have been served up a treat that will see us feast upon three El Clasico grudge matches in little more than a month.

As ever, the fixture promises to be a fascinating affair where anything can happen, as Lionel Messi and company take on Cristiano Ronaldo's Madrid mob.

So with the first encounter due to take place this week, we've taken a look at the five key battles to watch in the Copa del Rey semifinal first leg.

1. Mourinho vs. the Barcelona Coaching Staff

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Normally, we would bill this as Jose Mourinho vs. Tito Vilanova. But with the Barcelona boss undergoing medical treatment in New York, the responsibility of doing battle with the Portuguese falls to the Barcelona coaching staff as a whole. 

What generally makes this such a fascinating tactical fixture is that Real Madrid like to play on the counter attack, while Barcelona go on the offensive against everyone.

Will Barcelona go all out for a win at the Bernabeu, or play a little more cautiously to avoid being hit on the break? 

The reverse is also a fascinating question. If Mourinho plays cautiously, he runs the risk of travelling to the Camp Nou protecting only a home draw, or slender lead. Equally, if his side goes all out to win at home, Mourinho will know that it will leave the space that Barcelona could turn into an away win.

2. The Barca Attack vs. Lopez

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After the recent injury to Iker Casillas, Real Madrid wasted no time in buying a replacement, according to realmadrid.com, and it was someone that both Madrid and Barcelona know very well.

Diego Lopez should make his return in a Real Madrid shirt on Wednesday, having previously served as Casillas' understudy.

Now Lopez steps onto centre-stage against Barcelona, a team who he has excelled against in the past. In 2008, Lopez played in two legs for Villarreal against Barca, conceding only once in 180 minutes, as he made a string of saves that included stopping a Lionel Messi penalty.

Earlier this season, Lopez again thwarted Barcelona, according to goal.com, as Villarreal held them to a 0-0 draw. Can he keep Barcelona's attackers at bay once again?

3. Ozil vs. Busquets

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It might be Cristiano Ronaldo who grabs the headlines, but it is arguably Mezut Ozil who makes Real Madrid tick. 

Yet the German has not enjoyed great success against Barcelona, and it is Sergio Busquets who has been  the thorn in his side. 

Ozil loves to operate in space in-between the defence and midfield, but Busquets is the master of that particular domain at Barcelona. 

Will the Spaniard reign supreme again on Wednesday, or will Ozil finally find a way to dominate his rival?

4. Ronaldo vs. Alves

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A key attacking threat for Barcelona is normally the attacking runs made by their right-back Dani Alves. But this is a risky tactic if Mourinho decides to employ Cristiano Ronaldo on the left wing.

Ronaldo is at his most effective when finding space behind the full-back, before cutting inside onto his right foot.

Alves will need to curb his attacking enthusiasm, play much deeper and force Ronaldo to roam centrally in search of space. 

5. Messi vs. Real's Central Defence

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With Pepe out injured (at least that gives Real a better chance of finishing the game with 11 players) the jury is out as to who will play alongside Sergio Ramos in the centre of the Real defence. 

Ricardo Carlvalho was picked against Getafe at the weekend, but Mourinho might prefer a younger and faster option when faced with the might of Lionel Messi.

What we do know is that Madrid's central defenders will be all over Messi as soon as he gets the ball and will probably be assisted by someone dropping deep from the Real midfield. 

Mourinho knows that you simply cannot give Messi the time and space to run at players. Knowing this and stopping the Argentinian magician are two entirely different things, though.