Chelsea travelled to Greece on Wednesday ahead of our Europa League clash with PAOK on Thursday night.
Willian, who scored a brilliant goal on Saturday against Cardiff City, is expecting a difficult game when we face PAOK on Thursday.
“It will be a difficult game,” Willian said.
“I’m sure that we will play against a good team. They have players of quality and it will be a difficult game for us. We have to be ready. We want to start well, we want to start with three points.”
Willian, who is expected to start against PAOK on Thursday, also revealed Chelsea boss Maurizio Sarri has brought fun back to Chelsea after replacing Antonio Conte.
Willian fell out with Conte and revealed last month he would have quit Stamford Bridge had Conte remained as Chelsea boss.
“He wants us to play,” Willian said of Sarri. “You can see in the games the difference from last season.
“We play more, we have more possession, we enjoy, we have fun with responsibility. We win five games in a row so we have to continue the same way.
“I’m happy with the new manager, with the new profile of football. We have a great team atmosphere. We have great players. We can do everything this season to win titles.”