The Belgium international suffered an ankle injury in a controversial challenge with Liverpool's Sotirios Kyrgiakos in the Merseyside derby defeat at Anfield on Saturday. It is feared the 22-year-old could be out for a few weeks but Everton are still to learn the full extent of the problem.

Moyes said: "He was due to see a specialist in London but the train he was due to travel down on was cancelled, so he's missed his appointment time. He's booked in now for Thursday."

He added: "But he's got a really bad ankle. I was really surprised - it was like an elephant's ankle, it was that bad.

"The boy has got a bad-looking injury but until the specialist sees it we can't make any kind of decision.

"He has been integral part of how we have played in recent weeks and he will be a miss."

Fellaini's injury at least comes at a time when Everton have the strength to cover. The Toffees were hampered by injuries throughout the opening half of the campaign but Moyes spoke positively last week about how close he was to having a fully-fit squad.

Mikel Arteta, only recently returned from close to a year out with a knee problem, replaced Fellaini at the weekend and could continue after coming through unscathed.

Fellaini was hurt as both he and Kyrgiakos attacked a loose ball. Kyrgiakos was sent off for his part in the tackle but some observers have claimed Fellaini was equally to blame for the collision and argued that either player could have seen red.

But Moyes said: "I said it after the game, and I haven't changed my views, that it was a two-footed tackle off the ground (by Kyrgiakos). He was flying towards a player, he could see that coming all the way, so it was a sending off."