Andy Carroll's chances of securing a move to Chelsea have been hit by the news that he will be sidelined for about a month with an ankle injury.
Sky sources understand the striker, whom Blues boss Antonio Conte wants to sign on loan this month, will be out for about a month with the problem.
A scan had on Thursday confirmed the England international will not be able to play again until after the current transfer window has closed.
Carroll, who has struggled with injury problems throughout his time in east London, has been unable to train and missed West Ham's past three games.
Sky Sports News reported earlier this week that Chelsea had approached the Hammers for Carroll, who is valued at £20m.
It is understood West Ham will not sell him for less than his valuation but their stance could change if Blues striker Michy Batshuayi was included as part of the deal.
West Ham boss David Moyes was at Chelsea's FA Cup third-round replay win over Norwich on Wednesday but Sevilla are growing increasingly confident of signing the Belgian, who has struggled to cement a place in Conte's plans.