Since Barcelona's 5-0 win at the Camp Nou in Mourinho's first Clásico, Real Madrid has performed quite well in every match played at that stadium. Los blancos managed to draw or lose by a narrow edge until Cristiano Ronaldo silenced Barcelona's crowd in Real Madrid's 1-2 win to virtually clinch the 2011-2012 Liga BBVA title last April.
That game showed Mourinho's team was finally ready to take the final step needed to beat Pep Guardiola's team. After that, Barcelona's most successful coach in the history of the club left the team, and President Sandro Rosell decided to put Guardiola's second coach Tito Vilanova at charge. Real Madrid was able to get a 3-2 loss in the first game of the Spanish Supercup to then raise the title at the Santiago Bernabéu with a 2-1 win.
Even though Barcelona is leading the Liga BBVA table with an 8-point advantage to Real Madrid, they haven't been playing well. Their defensive line appears to be very shaky, and it will be very important to see if Gerard Piqué is finally able to feature, since Puyol has been ruled out after his terrible elbow injury.
This time, Barcelona has the edge. They could afford to draw the game to keep that 8-point lead while Real Madrid should go for the win to try to cut the lead to just 5 points. It's true that there's a long way to go, as both managers have said many times, but an 11-point advantage for Barcelona could be too much for Real Madrid.
Mourinho will probably keep the 4-2-3-1 formation he's used in every match but Manchester City's visit to the Santiago Bernabéu a couple of weeks ago. His team is certainly improving, so he might not need to switch to the 4-3-3 formation anymore. Real Madrid's coach was able to rest Sami Khedira, Ángel Di María and Mesut Özil against Ajax Amsterdam. Karim Benzema played the whole match, but he's been rotating with Gonzalo Higuaín during the Liga, and considering how good the French striker played against Ajax, it will be very hard for Mourinho to leave him on the bench.
Mesut Özil, Kaká and Luka Modric are competing for just one spot. Real Madrid's number 10 is always one of Real Madrid's best players against Barcelona. Luka Modric is still a long way from being the reinforcement Mourinho was hoping for, but he's had his good moments as well. The Croatian playmaker should be chosen if Real Madrid wants to have a higher possession percentage, since Özil is a little bit best suited for playing with a counterattacking style. Kaká played some good minutes in Madrid's win at the Amsterdam Arena, but that's probably not enough to leave both Özil and Modric on the bench.
The rest of the team seems pretty much decided. Álvaro Arbeloa, Pepe, Sergio Ramos and Marcelo would form Real Madrid's defensive line. Fàbio Coentrao is also ready to feature, but he hasn't played a single game for about one month. In the midfield, Xabi Alonso and Sami Khedira will try to stop Xavi, Iniesta and Busquets from creating good chances for Messi and the rest of Barcelona's strikers. Khedira has had an astonishing start of the season for Real Madrid, giving assists but also defending at a great level. His partnership with Xabi Alonso has been slowly improving week in and week out.
If Mourinho finally decides to play with a 4-3-3 formation with Khedira, Alonso and Essien, Di María and Ronaldo would be on the wings, since Di María's work-rate is always very important against Barcelona. Mourinho knows this, and that's why he only played Di María 30 minutes in Ajax's feud.
It will be very important to see how both teams start the game. Barcelona should try to control the game and play with Real Madrid's mind. But if Real Madrid is able to get the lead, it will be very hard for Barcelona to break Mourinho's defensive wall. As Mourinho said in Saturday's press conference, "you never know what's going to happen."