Mauricio Pochettino conceded Chelsea may be forced back into the transfer market for attacking reinforcements following the injury to Christopher Nkunku.
Real Madrid are reportedly poised to pursue a 'loan-to-buy' arrangement in their quest to acquire Chelsea's goalkeeper, Kepa Arrizabalaga.
Luton have signed former Chelsea and Everton midfielder Ross Barkley on a free transfer.
Chelsea could face punishment for breaching the Premier League's financial regulations during Roman Abramovich's ownership.
Chelsea have reportedly reached out to representatives of USA midfielder Tyler Adams regarding a potential transfer to Stamford Bridge.
Chelsea have secured the services of Brighton goalkeeper Robert Sanchez with a seven-year contract.