Fàbio Coentrao's recovery has given Mourinho more options for Tuesday's Clásico. Real Madrid's coach could line up two different 4-3-3 formations, one with Essien alongside Alonso and Khedira and the other with Luka Modric. Real Madrid needs to score, but the shortest way to the Copa del Rey Final could be preventing Barcelona from scoring and wait for the counterattack as AC Milan did in the first game of their Champions League tie against Messi and company.
Barcelona concedes goals quite frequently, so if Madrid manages to keep a clean sheet at the Camp Nou los blancos will be in a perfect situation. If Essien is the chosen one to play in the midfield, defenders Álvaro Arbeloa and Fàbio Coentrao would have much more help against Alba, Pedro, Villa and the rest of Barcelona's wingers. With Modric, Mourinho would lose that defensive presence that Essien provides, but the Croatian player would prevent Barcelona from having the ball as much. Modric likes to play with the ball, so this doesn't seem the right game for him, though.
The other option is to play with the usual 4-2-3-1 formation and press Barcelona's defenders. That turned to be a good strategy in the past few meetings, but Barcelona has always managed to score. Barça has always been seen as a positional team, but they are lethal in transition.
Those are the options Mourinho should consider, especially after seeing Milan destroying Barcelona at San Siro last Wednesday.