Chelsea boss Antonio Conte admitted Chelsea’s title challenge is all but over after the 1-0 defeat against West Ham at the London Stadium.
Conte’s side made a slow start and conceded within six minutes when Marko Arnautovic curled in a shot from the edge of the area for his first Hammers goal.
The Blues are 11 points behind leader Manchester City, who play their game in hand against Manchester United on Sunday.
Conte told Sky Sports: “We have to consider that if you lose four games in the first 16, my experience tells me that it is impossible to stay in the fight for the title.
“It means we must have another target.”
Conte said the opening stages cost Chelsea dear against a fired up West Ham side who were seeking a first win under new manager David Moyes.
“When you lose, there is a great disappointment,” he added.
“Our start was very bad because we conceded a goal. But we lost every tackle.
“At 1-0 down we tried but in this situation in a London derby it is very difficult. We had 19 shots but we didn’t score.
“Many players were tired and also made a lot mistakes with our final decisions but when you play every three days with the same players it can happen.”