Everton manager David Moyes admitted it was a "big blow" to lose on-loan winger Jack Grealish to a broken foot which has left a question mark over his immediate future.
The Manchester City forward was injured in last weekend's win at Aston Villa and diagnosed with a stress fracture after seeing a specialist, who will conduct further examinations before providing an estimate on how long he will be sidelined.
Not only is it a blow for Everton, whose loan agreement includes a £50m option to buy, but for any hopes the player had of making a late bid for the World Cup.
"It's not for me to give the timescales - we've not got it yet from the doctors - but he has a stress fracture in his foot, that's all I can tell you," said Moyes.
"It's a big blow because he's been hugely important to us since the start of the season, he's played a big part in the team."
Speculation this week suggested the lay-off could be as long as three months, but Moyes added: "I wouldn't say anything here at the moment. I wouldn't speculate and I wouldn't put any numbers to it."
The Everton manager said they were not thinking about the implications for Grealish's longer-term future at the club but admitted the injury may influence their January transfer window.
"Getting them is a different story but it will add to our thinking of 'is there anything out there we can consider'," he said.
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