Maurizio Sarri says Chelsea's downturn in form can be attributed to "blackouts", and admits he does not know how to beat a team coached by Pep Guardiola.
The Blues take on Manchester City this weekend at Stamford Bridge, and know that a defeat would leave them 13 points behind the reigning champions and all but out of the title race.
Chelsea go into the match having lost two of their last three Premier League matches and Sarri acknowledges his side are facing "big problems".
He said: "We have a problem to manage the match at the moment. In the last two matches we played well for 60 minutes, then in the first difficult moment we had a blackout.
"In the first match (against Fulham) we were lucky because they didn't score. In the last match (against Wolves) we were a little bit unlucky, because they have two shots on target and score both. After the first goal we went in blackout and were not able to react."
When asked how he planned on solving the 'blackouts', the Italian said: "It's not very easy to answer.
"I saw in the last matches when there is the first difficulty, we went in blackout. We didn't react as a team, but as 11 players in 11 different ways. So it's a big problem."
City will arrive at Stamford Bridge in ominous form, having won 13 and drawn two of their 15 Premier League matches this season - recording a goal difference of plus 38 in the process.
Equally troubling for Chelsea is Sarri's record against Guardiola - three defeats in three matches - and it is a record Sarri is unsure how to end.
Asked how he planned to beat City on Saturday, Sarri said: "I don't know. Against Guardiola I lost every match, so you'll have to ask somebody else!
"The match is really very important. It is a very difficult match against maybe the best team in Europe.
"It's impossible to beat them in a long period but in a match, everything can happen."