Everton interim manager David Unsworth has confirmed that both Leighton Baines and Michael Keane could be facing spells on the sidelines.
Left-back Baines was forced off after just 27 minutes of the Toffees' 4-1 defeat at Southampton after suffering a calf injury.
Centre-back Keane, meanwhile, was substituted 15 minutes from the end of the Premier League game at St Mary's after picking up a knee injury.
Speaking after the game, Unsworth said: "Leighton has done his calf unfortunately. We'll probably assess him more tomorrow.
"He said he felt his calf pop which is never a good sign, a muscle injury like that so early in the game. We'll reassess him but he looks like he'll be struggling for Wednesday.
"Michael was a bit different. I don't know whether it was concussion. I've not spoken to Michael or the doctor. He was with the doctor in the changing rooms at the end of the game and I haven't had chance to speak to either yet."
Everton remain 16th in the table following the defeat on the south coast, just two points above the bottom three.