Issa Diop could well return to the team on Thursday when the Hammers take on Sevilla in the Europa League.
The Frenchman has impressed on recent occasions and has chances of a return against Sevilla should Moyes reverts to a five-at-the-back formation.
Sevilla progressed to the Round of 16 despite a 1-0 loss to Dinamo Zagreb and Moyes is likely to be well aware of the fact that the Croatians Zagreb played five at the back.
It means Diop would join Craig Dawson and Kurt Zouma in central defence, with Ben Johnson the right wing-back and Aaron Cresswell the left wing-back.
With both Jarrod Bowen and Declan Rice potential absentees, it would also allows the Hammers to utilise real width without having to rely on Said Benrahma, and to protect goalkeeper Lukasz Fabianski.
Tomas Soucek will likely be joined in midfield by Manuel Lanzini, with Pablo Fornals deployed as the attacking midfielder should Declan be unavailable.
That leaves two forwards, and Mikey Antonio is likely to be joined by Nikola Vlasic, a player with a real point to prove, in the likely absence of Bowen.