Speculation has been rife this summer that Courtois is angling for a return to the Spanish capital - where his children live - with Real Madrid heavily linked with a 35-million-euro move for the Belgium global.
And it is understood the Blues do not know when the 26-year-old Belgium global will return.
The wide man said: "I was always clear about wanting to stay here".More news: City back in the groove as Aguero ruins Sarri’s Chelsea bow
The Belgian greatly enjoyed his loan stint with Atletico Madrid a few years back and has his family still living in the Spanish capital now. Chelsea risk losing him for a reduced fee in January or for free next summer.
Sarri admitted there was "a little difference, maybe a lot" between the two teams at Wembley but said he had had little time to work with the players, many of whom were given extended holiday after the World Cup. But I have my head here and I intend to continue in the club unless the club wants to sell me.
Chelsea, who are looking to improve on their fifth-placed finish last season, kick off their league campaign with a trip to Huddersfield Town on August 11.
Speaking on Friday, new Blues manager Maurizio Sarri said he was unsure whether Courtois would stay.More news: Demi Lovato agrees to check into rehab immediately after hospital
The possibility of Willian ending his five-year spell in west London had looked more likely following the breakdown in his relationship with former manager Antonio Conte.
According to ESPN, Belgium worldwide Thibaut Courtois has made it clear to his manager he wants to move to Spanish giants Los Blancos.
While Courtois is attempting to engineer a move away, Hazard has decided not to agitate for his own switch to Real.
"I don't think I should comment too much about that in this moment because we are at a delicate time in the process".More news: RBI hikes key rate 2nd time in two months
Securing a replacement for Courtois will be Chelsea's top priority in the coming days, sources told O'Rourke, with the Blues set to open the Premier League season at Huddersfield on Saturday.