Willian has confirmed on Facebook that his mother has lost her battle with cancer after surgery and chemotherapy treatments failed to send the disease into remission.
The 28-year-old revealed that his mother, Dona Zeze, 57, was suffering from the illness back in September and that she was receiving treatment in his native Brazil.
He's no longer expected to feature against Leicester on Saturday having been given compassionate leave by Chelsea, but he played and scored in Brazil's 2-0 win over Venezuela on Sunday.
In his last Premier League game against Hull City, Willian told Chelsea TV that his breakthrough goal was dedicated to his sick mother as he did his trademark pointing to the sky celebration after initially cheering with his teammates.
Willian previously told how his mother had a 'two-and-a-half-year struggle' with the illness and she will be buried on Thursday in the Ribeirao Pires district of Sao Paulo.
Upon confirming the news, Willian posted a poem to his social media accounts to commemorate his mother and confirmed that he is in a period of mourning while Chelsea issued the following statement.
"All of us at Chelsea Football Club are sending our love and deepest condolences to Willian and his family after the passing of his mother.
We are thinking of you Willian."