The 59-year-old Italian, speaking at his unveiling after being appointed the successor to sacked compatriot Antonio Conte, admitted to being disinterested by the transfer market.
"I can not change 20 players, I must adapt and then I will see if we change something in my game". Chelsea are all set to face a massive shift in the current transfer market with a host of their players linked with a move away from the club.
That would make him the second most expensive player of all-time, behind PSG winger Neymar.
Gianfranco Zola has been named Chelsea assistant first-team coach to new boss Maurizio Sarri.
Cesc Fabregas has promised Chelsea fans he is doing all he can to convince Eden Hazard to stay at the club.
Sarri, who forged his reputation in charge of Napoli guiding them to runners-up twice and third in his other season, said of course it would be for the better to keep the best players.
The Blues have only signed Italy global Jorginho in a £57m deal from Serie A runners up Napoli in the summer transfer window so far. Conte's clashing with the Stamford Bridge board on player purchases and sales partially led to his demise as Chelsea manager.
On Cahill, Sarri said: "I think he can still give us a lot". "Those that know me well can not define me in this way. I hope to do it in a few weeks".
Chelsea start their pre-season tour with a game against Perth Glory in Australia on Monday before travelling back to Europe to play against Inter Milan, Arsenal and Olympique Lyonnais.
With the 22-year-old uncertain of achieving anything remotely similar at Real Madrid, the move to Chelsea could be appealing.