Chelsea boss Frank Lampard has been told he can only make one signing during the January market.
Lampard was informed of the decision by managing director Marina Granovskaia going into yesterday's defeat at Arsenal.
The Athletic reports Granovskaia will only sanction a move for Declan Rice.
The West Ham star was released by the Blues academy in 2014 and fits the mould for the exact type of player they are looking to recruit.
The midfielder has yet to reach his peak and he would be an investment for many years to come.
But it will not be easy to convince West Ham to sell Rice, as manager David Moyes issued a warning earlier this year.
The Scot said, "Declan was reassured when he signed a five-year contract, when you do that you decide you are committed to the club. If somebody then turns up and offers you a bundle of cash, that's the club's decision.
"I think Declan is the future captain of West Ham going forward. When Mark Noble comes to an end I think it will be Declan Rice.
"We have no intention of letting him go but if it does come it will need to be 'Bank of England' money."