Chelsea face having to upgrade Willian's deal if they want to keep him away from Manchester United.

Willian was linked with United yesterday amid Jose Mourinho's appointment.

The Daily Star says the 27-year-old is becoming frustrated with the fact no new contract has been offered to him, despite a superb season.

Willian earns £85,000-a-week - less than half of Eden Hazard - and wants a huge pay rise as a reward for his fine form.

United and Mourinho are watching developments closely.