Chelsea will be without Willan as they take on Watford tonight, in what could be a tough London derby.
The Blues travel to Vicarage Road tonight, as they look to continue their resurgence under caretaker boss Guus Hiddink.
Chelsea have remained unbeaten since the Dutchman returned to the club around six weeks ago, but are still yet to win back-to-back matches in the league at all this term.
Watford are no pushovers either, having only conceded in six of their 12 home fixtures so far this term, and currently sit comfortably away from the drop-zone in 10th position.
The Blues will be keen to continue their form, but will have to do it without their most consistent player this year, Willian, who picked up a knock against Milton Keynes Dons on Sunday.