Diego Costa admits he returned to Chelsea out of shape this summer.
The Spanish striker has been well below his best in the early stages of the new season and has revealed that he may have been a little complacent after firing the Blues to the Premier League title last term.
"I'm going to be very honest," said Costa. "Five or six weeks ago, I was not on top of my game, at least physically.
"I got injured at the end of the season and then I went on holiday. Maybe I got out of my diet and when I came back I was not the way I was supposed to be. I was a little bit overweight, and that affected my game.
"You can be selfish and blame it on the manager but I'm not going to do that. I'm responsible and so are the other guys. We need to blame the players.
"We know we were not 100 per cent when we got here. We came back from holiday very confident, and thought we could go back into how it was last season. When we actually realised where we were, the team was already in a bad situation."