Chelsea defenders Andreas Christensen, Antonio Rudiger and Azpilicueta will not be allowed to discuss new contracts with the Blues after the UK government imposed sanctions on owner Roman Abramovich.
The UK government has confirmed that Abramovich has been added to the list of individuals who will be sanctioned.
The decision has implications for how Chelsea can operate on a day-to-day basis, with Chelsea understood to be meeting government officials on Thursday.