Midfielder Kovacic is on loan with the Blues this season and he will be allowed to make a permanent move in the summer should Sarri decide he wants him.
Whether he is included in as part of a Hazard bid or a transfer is negotiated separately, Real will hope that Kovacic can help them cover the cost of any deal for Chelsea’s star man.
Despite the fact they are trying to sign a striker and a midfielder this month, Hazard’s future remains Cheslea’s number one priority.
The Blues hope to find out later this week whether they can make progress on a deal to sign Gonzalo Higuain, which would allow Alvaro Morata to leave the club. Sevilla have ruled themselves out of the running for Morata, but Atletico Madrid remain interested.