Who plays at Centre-Back?

In pre-season it looked like we might struggle in the centre of defence, but now with MARK (79), TEWIT (24) and M (4) all vying for a start (and thats even before Tomilinho comes back!) we needn’t have worried! Which partnership do we play? TEWIT (24) has an unbelievable work rate and was a key player for us last season. M (4)’s experience shines through, he's always reliable and adds a bit of aggression to the backline. MARK (79) is the new boy, but his recent displays prove how well he's settled in. Who do you think should start?