Willian has said he has found it hard to play for Chelsea in recent weeks as he is still struggling to deal with the death of his mother.
Chelsea granted Willian compassionate leave in October to remain in Brazil after the international break and attend the funeral of Dona Zeze, who died aged 57 following a two-year battle with cancer.
Pedro Rodriguez replaced Willian in Antonio Conte's starting XI and performed well as Chelsea maintained a Premier League winning streak that now extends to 11 matches, lifting them six points clear at the top of the table.