Blues manager Maurizio Sarri has admitted he will not keep the Belgian against his will.
Neymar could leave Paris Saint-Germain, while Real Madrid want Eden Hazard.
Thibaut Courtois and his teammates will "fight" for Antonio Conte the same way they did for José Mourinho in 2015, the goalkeeper says.
The Italian has guided Chelsea to the top of the Premier League.
The Italian has taken the club from 10th place to 10 points clear at the top of the Premier League.
Thibaut Courtois and Eden Hazard could leave.
The Spanish giant wanted a Premier League star.
The transfer window closes on January 31.
Costa was absent for Chelsea's victory over Leicester.
David Luiz and Marcus Alonso moved to Stamford Bridge.
Thibaut Courtois believes change at the club was inevitable.