Willian believes Maurizio Sarri has brought the fun back to Chelsea since replacing Antonio Conte as manager in the summer.
Conte fell out of favour with key figures, which includes Willian, of the squad last term and was sacked in July after two years at the helm.
Willian revealed last month that he would have quit Stamford Bridge had Conte remained in his job amid interest from Barcelona and Manchester United, but such talk is all in the past now that Sarri has changed things around.
The Blues are top of the League after five straight wins and are playing some of the most entertaining football in the division.
When asked what impact Sarri has made, Willian said: “He wants us to play. 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.
“I‘m very proud to stay and to be a Chelsea player. It’s an honour to play for this club. I’m very happy at Chelsea.
“Everyone knows what happened in the last transfer window but my mind was always at Chelsea. It was always to play for Chelsea. Now with Sarri we have a different way to play football so we just want to enjoy and continue to play for this club.”
Willian is set to start tomorrow night as Chelsea take on Paok Salonika in their opening Europa League group game.
He added: “It will be a difficult game. 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.”
