Antonio Conte said Chelsea's hopes of defending their Premier League title are gone following a surprise 1-0 defeat by struggling West Ham on Saturday.
The 48-year-old Italian told Sky Sports that Chelsea's fourth defeat of the campaign had dealt a killer blow to their chances.
Marko Arnautovic's sixth-minute strike was enough to see off a lethargic Chelsea side and give West Ham only their third win of the season.
"We have to consider that this is the fourth game we've lost in 16 games," said Conte.
"In my previous experience, it won't be possible to fight for the title. With four defeats in 16 games, we must have another target."
That target, he told the BBC, is now to ensure there is Champions League football next season.
"There are six top teams and four go to Champions League," said Conte, who blamed fatigue for his players under-par performance.
"We have to fight and do our best."
His downcast appearance was in stark contrast to his West Ham counterpart David Moyes, who saw his players succeed in holding onto a 1-0 lead unlike last weekend when they allowed Manchester City to come back and win 2-1.
"The win, the spirit of the team, how they stuck together and more that importantly a lot of the basics were done well today -- all that really pleased me," Moyes, who replaced the sacked Slaven Bilic last month, told Sky Sports.
Victory was not enough for the Hammers to climb out of the bottom three but Moyes -- who is aiming to succeed where he failed with Sunderland last season by keeping West Ham up -- can see brighter times ahead.
"We got a big boost from the performance at Manchester City, that was something we could talk about positively, and we do have the players to threaten in attack once we get the back end sorted out," he said.