Everton will have to wait until next week to discover the extent of Marouane Fellaini's ankle injury.
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."