Chelsea ace Willian concedes Manchester City could already be out of sight in the Premier League title race.

Willian admits opposition teams have raised their game against the champions.

"It's difficult," he told BBC's Football Focus when asked if Chelsea can retain the title.

"Manchester City are playing very well but I think we can fight for the title until the end."

He added: "It is difficult to play when you were champion last season and to fight for the title again as every team wants to win against Chelsea."