The French left-back faces up to three months out and Carlo Ancelotti may now need to employ a wing-back system.
Everton left-back Lucas Digne is facing up to three months out with an ankle injury to give manager Carlo Ancelotti a decision to make ahead of the visit of Leeds.
Last week the Italian changed to a wing-back system and with the inexperienced Niels Nkounkou his only cover on the left he may be tempted to employ the tactic again.
Right-back Seamus Coleman (hamstring) is still not fit while long-time absentee Jean-Philippe Gbamin (Achilles) remains a couple of weeks away from being in contention.
Leeds head coach Marcelo Bielsa is expected to choose from an unchanged squad, with no new injury concerns following last week's goalless home draw against Arsenal.
Midfielder Pablo Hernandez remains sidelined with a muscle strain and defender Diego Llorente (groin) is still not in contention to make his club debut.
Midfielder Jamie Shackleton (thigh) is also still out, while club-record signing Rodrigo is pushing for a recall to the starting line-up having recovered from coronavirus.
Everton provisional squad: Pickford, Keane, Mina, Holgate, Kenny, Allan, Doucoure, Iwobi, Rodriguez, Calvert-Lewin, Richarlison, Olesen, Godfrey, Gomes, Sigurdsson, Davies, Tosun, Bernard, Gordon.
Leeds provisional squad: Meslier, Cooper, Koch, Dallas, Ayling, Klich, Phillips, Alioski, Bamford, Struijk, Harrison, Costa, Rodrigo, Raphinha, Roberts, Casilla, Casey, Poveda, Davis.