I thought it would be worth revisiting this now we have a new Head Coach. Bilic has regularly played a 4231 throughout his career so here is what we currently have left fitting into this system:
Johnstone/Bond/Palmer
Nyom/Wilson
Dawson/Bartley
Hegazi/Fitzwater/O'Shea
Gibbs/Townsend
Livermore/Field
Phillips/Edwards
Harper
Brunt/Leko
Rodriguez/Rondon/Robson-Kanu/Burke
I have included those out on loan like Rondon and Nyom. A cursory look at the squad list above shows that we are short of numbers in the central midfield areas. Obviously there are the likely departures of Rondon, Harper and others. Let's say the following players leave: Nyom, Harper, Rondon and Rodriguez (that may be conservative), our best XI would look like this:
Johnstone
Wilson
Dawson
Hegazi
Gibbs
Livermore
Field
Phillips
Edwards
Brunt
Robson-Kanu
Looking at that we would need a starting right back, an upgrade in the defensive midfield department or certainly more options, a central attacking midfielder and a starting striker.