Chelsea reportedly risk missing out on top transfer targets Robert Lewandowski and Jean Michael Seri due to the uncertainty over their next manager.
The Blues have so far stuck by current boss Antonio Conte, despite long-running rumours that he will be axed prior to next season.
Ex-Napoli boss Maurizio Sarri is rumoured to have been lined up to succeed Conte, but Chelsea must first work out a compensation package with the Italian club, on top of paying off Conte and his coaches.
Both players are said to be concerned by the situation, as they are unsure whether they are being signed by Conte or Sarri.
A separate report claims that Sarri's agent arrived in the English capital on Tuesday to help finalise a deal.