I think potentially something like this could be an option with how everyone's playing at the moment, albeit a little left-field:
_ _ _ _ _ _ _ _ _ _ Pereira _ _ _ _ _ _ _ _ _ _
_ _ _ _ Burns _ _ O'Connor _ _ Williams _ _ _ _
Yiadom _ _ _ _ _ _ Fraser _ _ _ _ _ _ Ritchie
_ _ _ _ _ _ _ Wing _ _ _ _ Savage_ _ _ _ _ _ _
_ _ _ _ _ _ _ _ _ _ Doyle _ _ _ _ _ _ _ _ _ _
_ _ _ _ _ _ _ _ _ _ Marriott _ _ _ _ _ _ _ _ _ _
I think Burns and Williams haven't done enough to be dropped; O'Connor is probably our best centre-back. Three at the back could also assist in our defensive troubles.
The wing-backs of Yiadom and Ritchie would be able to get into advanced positions, whilst providing defensive cover. A midfield four provides the flexibility for players to switch around as the game progresses - sometimes a diamond; sometimes two twos; sometimes a flat three and a one; etc.
Marriott is probably obvious up top at the moment.