The Belgian's agent, Christophe Henrotay, has confirmed his client wants to join the European champions in order to be closer to his children, who live in Madrid.
Brazil worldwide Willian, who played at the 2018 FIFA World Cup for his country, was due back in England last Friday but did not turn up for pre-season training until Wednesday afternoon as he reportedly had some issues with his passport.
Courtois previously spent three years at Atletico Madrid and now is ready to link up with their city rivals.
"For him, this is a big decision because he wants to be near his family", he said, adding, "there is an offer in place [from Madrid] for Chelsea to accept".
Despite their Courtois stance, Chelsea are less reluctant to allow Hazard to leave and hope to tie their star winger down to a new-and-improved long-term deal.
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Republicans have been hesitant to request those records, however, and have accused Democrats of engaging in stalling tactics. He said he could not reach an agreement with Feinstein over the scope of the documents request.
Thibaut Courtois is due to return to Chelsea training this weekend after helping Belgium finish third at the World Cup and being voted the best goalkeeper at Russian Federation 2018. "It's very important for us to keep the top players".
In case he leaves, Chelsea have to quickly complete the signing of another goalkeeper in the remaining days as their back-up options - Willy Caballero and Robert Green - are not up to the mark.
The Blues can not afford to offload Courtois unless they find a good replacement this summer.
Alvaro Morata and Olivier Giroud remain at the club and with Willian, Eden Hazard and Pedro all risky in the final third, Chelsea should cause problems for several other defenders.