Claudio Ranieri admitted Leicester had only themselves to blame for the latest setback in their lacklustre defence of the Premier League title.
Ranieri's side slumped to a 3-0 defeat at Chelsea on Saturday and are languishing 10 points behind leaders Manchester City just five months after becoming English football's most unexpected champions.
Retaining the title was always likely to be a bridge too far for Leicester, but the depth of their struggles -- they have won only twice in eight matches -- is still a surprise.
Foxes boss Ranieri had no doubts his players were the authors of their own misfortune and he called on them to cut out the careless mistakes and show better focus.
"We made mistakes. When you concede a goal from a corner again it is clear. You come to Chelsea and your attention must be at the maximum," Ranieri said.
"If we scored the goal when we create a chance we can re-open the match. But our approach to the match was not good. Maybe we were a little nervous.
"We tried to react and the second half was much better."
It was especially galling for Ranieri to see Chelsea midfielder N'Golo Kante, so influential in Leicester's title triumph, dominate against his former team.
"We miss him, but we have to play better. We must concentrate more," Ranieri said.
"It is better that this happens now, so we can react, than at the end of the season."
After a week in which Chelsea manager Antonio Conte endured speculation he would be sacked after bookmakers suspended betting on his dismissal, the Italian was delighted by his side's most vibrant display of his brief reign.
"It was a good game. From the start I asked them to play well with intensity and to try to do what we are doing in training," he said.
"I am very happy because I had a good reply. This is the best game for us. I saw good commitment. When you work hard it is important to have a good performance.
"In the week we tried a lot to find a solution that gave us more compactness. For this team and squad this system is the right fit.
"The coach must understand and find the right suit. We are like a tailor."
Meanwhile, Eden Hazard revealed he held two fingers aloft on each hand after scoring his goal in a tribute to Chelsea team-mate Willian, who missed the match to fly home to Brazil after the death of his mother.
Willian, who wears the shirt number 22, lost his mother to cancer this week.
"My celebration was for Willy. He lost his mother and we are thinking about him. We hope he can come back stronger," Hazard said.