Sergio Ramos vs Pedro
The man very much forgotten at the head of the Barcelona side, in among Lionel Messi and David Villa, is Pedro. Whereas the aforementioned duo combine flair and true world class ability in the final third, Pedro is more workmanlike at the top end of the pitch, hassling defenders in mistakes as well as being clinical in front of goal.
In Ramos, he has an opponents he'll see little change out all evening. The tall but subtly quick Ramos has the physical presence to dominate his Spanish counterpart, but Pedro's agility will cause problems.
Xabi Alonso vs Xavi
These two pass masters will make both of these sides tick in this two-legged semi-final. Alonso has lived in his good friend's shadow internationally for some years, but he has the chance to level the playing field at the Bernabeu.
The former Liverpool midfielder is likely to sit deeper in the absence of Sami Khedira, putting him on collision course with Xavi, who is likely to spend plenty of time getting forward.
Cristiano Ronaldo vs Carlos Puyol
If Ronaldo is again preferred up front he'll come face-to-face with the fit again Puyol, who missed last week's Copa Del Rey final. The ease at which Ronaldo let to head in the winner in last weeks final at the Estadio Mestalla highlighted just how much Barcelona, despite Gerard Pique's continued development, miss the Spanish captain.
In a foot race there is no doubt Ronaldo would overawe Puyol, but what he loses in pace he more than makes up for in positional sense, strength and commitment to the cause, attributes that may make his Portuguese opponent wary.