Chelsea boss Thomas Tuchel has spoken on his side's 1-0 loss to Manchester City on Saturday.
A Gabriel Jesus strike in the second half was enough to split the two teams as the Blues fell off the top of the Premier League table.
The result inflicted just their first loss of the season.
Speaking to the media ahead of his side's Champions League clash against Juventus, Tuchel reflected on the weekend defeat.
He said: "We were not happy with our defensive, we were too passive against Man City.
"The defensive choices, the plan and my responsibility maybe led to this passive behaviour which was not the plan."
Chelsea failed to cope with the constant City press right from kick off and a change in formation, which saw a midfield trio as opposed to a front three, saw the hosts struggle when it came to creating chances going forward.
City were finally able to get one over Chelsea having lost the previous three meetings between the two sides, including the Champions League final in May.
Tuchel added: "The best way to defend is having the ball. This is what City did excellent.
"They had a very strong performance, we underperformed but they made us underperform. There is enough room to bounce back, it is necessary to show."
The Blues will be keen to bounce back from their loss with a win on Wednesday night against Juventus.
It will be their second game in Group H of the Champions League, with the reigning Champions having already beaten Zenit 1-0.
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