The 22-year-old was hurt in a controversial challenge with Liverpool's Sotirios Kyrgiakos in last weekend's Merseyside derby defeat at Anfield.

It is feared the Belgium international could be out for a few weeks but Everton want the player to see a specialist.

An appointment in London earlier this week had to be rearranged because of a problem in travelling on the train and the session has now been put back again.

"We have put Fellaini's appointment back until the swelling goes down a bit more," manager David Moyes told the club's website, www.evertonfc.com. "We don't want to speculate until then."

Moyes described Fellaini's injured joint last week as looking like an "elephant's ankle".

Fellaini has been one of the driving forces behind Everton's recent revival.

The Toffees have recovered from a poor start to the season to push themselves up to ninth in the Barclays Premier League after losing just once in 11 games.

Fellaini's absence for Wednesday's memorable defeat of Chelsea at Goodison Park at least allowed Mikel Arteta to make his first start in almost a year.

The Spaniard, who suffered a serious knee injury last February, played for 73 minutes against the league leaders and came through unscathed.

Fellaini's likely absence means he could now keep his place for Tuesday's Europa League tie against Sporting Lisbon and the clash with Manchester United the following weekend.

Arteta said: "It's all coming thick and fast but that is the only way to get back.

"They are both tough games, but that's what you want to get fit - to play the full 90 minutes and get into the condition I want.

"It's been a really tough time, I have missed playing all games not just the big ones.

"And to have the chance to play - even though I know there is still a lot to come - it was a great pleasure and I really appreciate the confidence from the manager."

Meanwhile Moyes has championed the World Cup claims of left-back Leighton Baines.

The former Wigan player could come into the reckoning for a place in England's squad for South Africa following injury to first choice Ashley Cole.

Cole faces a race against time to prove his fitness to Fabio Capello after breaking his ankle against Everton in midweek.

Moyes, speaking before Cole's injury, said: "I think the England left-backs will be Ashley Cole and Wayne Bridge and then I think it is toss-up between Stephen Warnock and Leighton Baines.

"I think Bainesy on his day is a match for any of them and I know Fabio Capello knows about him. He is certainly in and around the reckoning.

"He has been a very consistent player for us this season, as he was last year.

"I think Bainesy is one of the players who has kept a good level of performance even when things weren't going well."