The Blues midfielder was the club’s best performer last season but has experienced a spell on the sidelines due to struggling with the emotional time in his life.
Chelsea have been on an 11-match winning run and Willian is now keen to get back into the first-team and help Antonio Conte’s side.
“It has been a difficult time for me. I lost my mum. It has been very difficult emotionally,” he told the Daily Express.
“She was very important to me and she always will be.
“I have to think only about the good things and to keep working, keep playing”
Chelsea ace Willian
“After she died, I stayed in Brazil for a week. It was difficult coming back to training but slowly I have recovered, started to feel better and to feel I can play for the team.
“Now I have to think only about the good things and to keep working, keep playing. That’s what I want to do.
“The manager talked to me and told me to stay concentrated, to work hard in training, and when I come back into the game, to do my best. He has helped me.”
Willian returned to the starting line-up against Crystal Palace at the weekend and opened up on the challenge that provided him with.
He added: “It was difficult against Crystal Palace, especially for me after a long time without playing 90 minutes. We did well to win again.
“Now we have to try to keep doing the same thing – taking it game by game.”
Chelsea return to action on Boxing Day when they welcome Bournemouth to Stamford Bridge.