G.K.Formation inspired by Brazil under Dunga and also Barcelona. Wide forwards, central free man, DM dropping into defence, shuttler - these are all features. New signings (Azpilicueta, Sissoko, Hulk) are all realistic.
Role of each player:
Cech - Need I say more?
Azpilicueta - Be a solid RB, tuck in alongside the CB's if needed, perhaps attack if others drop back.
Ivanovic - Key CB - Be everywhere, marshall the lines.
Luiz - Cover LB zone when defending.
Romeu - Drop into the CB line while defending. Initiate attacks.
Sissoko - Perform a DM role while defending, reading and breaking up the game, push on while attacking.
Ramires - Be a DM while defending, but high-up right wing on attack - role requires such an amount of energy that he'll need to be replaced after ~70 mins
De Bruyne - Threat high up on left flank, also press RB.
Mata - Do whatever he wants, only remit is try his best to draw CB's out of position.
Hulk/Marin - Run into space from out wide to function pretty much as forwards.
Subs - Courtois, Cahill/Terry, Cole, Krasic, Meireles, Piazon, Sturridge
Bench allows change to 4-2-3-1
G.K.Oh, and Krasic in that list of new signings.