CB: Laurent Koscielny v Gerard Pique
Given that Arsenal have just suffered a humiliating 6-0 defeat at the hands of Chelsea (the third occasion on which they have shipped five goals or more to Premier League title rivals this season), the inclusion of a Gunners centre-back has the potential to ruffle a few feathers.
However, those woeful results aside, Koscielny has been very impressive this season and has elevated himself beyond the likes of Nemanja Vidic and Gary Cahill.
Meanwhile, in La Liga it now becomes a contest between international teammates Pique and Sergio Ramos - and we've opted for the former.
The toughest selection so far, in our opinion. Koscielny has really impressed at times this year and partner Per Mertesacker could just as easily have merited inclusion.
However, we're just going to give the edge to Pique here as he continues to marshall the Barcelona defence in the absence of a proper central-defensive ally. El Clasico XI are on the board, folks...