And Blues’ stars have got the clear message to improve urgently, according to defender Marcos Alonso.
Italian manager Sarri accused his players of complacency after they blew a stack of chances at 1-0 to lose 2-1 at promoted Wolves.
Sarri was also unhappy Chelsea lost their pattern of play and possession game when Wolves equalised.
Chelsea’s squad were duly hauled straight back in for training on Thursday ahead of City’s visit on Saturday.
After a second defeat in three Premier League games, Alonso admitted: “We’re not doing very well at the moment.
“We have to get better as a collective. The last few games we were not loyal to our style of play even if we didn’t deserve to lose.
“We are going through a hard moment and you have to work very hard, stay together and get back to winning as soon as possible.
“We have to play more as a team. It’s something we have to analyse, we will try our best to improve as soon as possible.”
The shock defeat after Ruben Loftus-Cheek’s early opener saw Chelsea slip to fourth and leaves them ten points behind leaders City.
It was their second successive defeat on the road after also losing 3-1 at Tottenham.
Sarri is now planning further changes after making five at Molineux where Alvaro Morata and Willian both returned to the line-up but failed to seize the opportunity.
Morata was especially wasteful as he failed to hit the target with two good chances early in the second half – including a seeming tap-in before Wily Boly intervened.
The pair were subbed and Olivier Giroud is now favourite to start upfront against the champions in place of the £60million Spaniard.
Sarri described Pep Guardiola’s men as arguably the best team in the world and they present an intimidating prospect for any side – let alone one out of form.
But Alonso, 27, insisted: “It’s the perfect opportunity to come back. It will be a great game for sure, everyone will be very motivated to play.
“We are very disappointed after the defeat but it’s back to work and we will work harder and start playing better as a team.
“If we lose we are going to be 13 points from the top and that’s a lot of points but we have to think, prepare for the game well and not pay attention to the table at the moment.”