I guessing the midfield
Midfield:
----------------Sissoko(DMF)----Melo(DMF)------------
Alexis Sanchez(RMF)-------------------Mesut Özil(LMF)
or:
------------------Melo(DMF)-----------------------------------
---------------------------------Marchisio(CMF)---------------
Alexis Sanchez(RMF)----------------------Mesut Özil(LMF)