Chelsea boss Jose Mourinho says Yohan Cabaye's move from Paris Saint-Germain to Crystal Palace shows that there are no easy teams in the English Premier League.
The Portuguese will again be in charge of the Blues as they will kick-off their official campaign on Sunday against Arsenal at Wembley.
He says the Premier League has become extremely difficult to win with at least five teams favourites to become champions at the end of the season.
"Clearly, five teams can win the title. One of them will be champion, and one of them will not even qualify for the Champions League," Mourinho told ESPN.
"So two years ago, Manchester City were champions and Man Utd out of the Champions League. Last year Chelsea were champions and Liverpool were out of the Champions League. And next season somebody will be champions and somebody will be outside of the Champions League.
"[Yohan] Cabaye at Crystal Palace, a player that left Newcastle two years ago to go to Paris Saint-Germain to get lots of money on a big transfer fee, is coming to Crystal Palace.
"The players that are going to Stoke; the players that are going to Everton; with the players that are going to every club in the Premier League it is getting much more difficult.
"So, that's what I felt last season, and that's what I feel this season. At this moment the Premier League is the top competition, and it's very, very hard."