as i see it...barca is a very attractive attacking team...busquet n mascherano can play as CB cum DM...they play total football of the dutch in spanish way...get the ball...n everyone in attacking mode...opponent hav the ball all turn to defending mode...every player from striker try to win ball back...villa messi every single player...chase the ball n get it back...maybe they only need 1 pure CB at the back...but pique also hav the quality to attack...its the philosophy of the club...i dont see any problem for cesc to slot in the middle along side xavi n iniesta...they hav develope the basic mentality from kids...its how they play...everyone know every movement of each other...they hav develope it for a long long time...

just my 2 cents.

i think they can play together xavi/iniesta/cesc in the middle...they r such a mobile team that always move...at the back they can play busquet/mascherano/keita as CB cum DM to partner pique/puyol...for me...i see them play like this

valdes

alves - pique/puyol - *busquet/mascherano - abidal/adriano

cesc - xavi - iniesta

alexis - messi - villa/pedro


thiago can fit anywhere in the middle
affelay as well can play in midfield or winger(mostly)

valdes

alves - pique/puyol - abidal/adriano

* busquet/mascherano

cesc - xavi - iniesta

alexis - messi - villa/pedro


busquet n mascherano can start as CB...in the game...if they hav the ball...both of them can slot to DM position to support the middle as their breather or slow the tempo a bit...they're such a fluid team that play as total...their striker is their first line of defender...to protect the defence...they must win the ball back early in the up field...

another my 2 cent...ahahaha