Thomas Tuchel was left baffled by Chelsea's performance in their 1-0 Champions League defeat at Juventus.
When asked what the reason was for Chelsea's below-par performance, Tuchel conceded he did not "know why" they had performed so poorly in Turin.
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"I think we started not sharp enough. We struggled to create our own rhythm and intensity because they were so deep and passive. We were lacking runs. We were so good in training yesterday and not good enough, not free enough today. I don't know why," Chelsea's head coach said.
"I felt we were a bit slow and tired, mentally slow, decision-making. That's why it's a strange one to analyse. We had a day off and two very good training sessions yesterday. We were absolutely sharp, looked very fresh and very hungry, and ready for a bounce back.
"It's very difficult to put on a high rhythm against a team who defends so deep. If we defended deep against City it was difficult for them to create chances. It was the same for us here. But the difference was we gave two big chances and gave the belief back into the stadium."
Chelsea managed to register just a single shot on target at the Allianz Stadium, despite dominating the ball with over 70 per cent possession.
They met a typically tough Juventus rearguard after Chiesa's opener, and Tuchel conceded his side found it difficult to break down their opponents - just as they found last weekend in the Premier League.
"Manchester City scored from a set-piece with a deflected shot against us. Sometimes you need this. If a team defends deep, it's hard to find your own rhythm," Tuchel added.
"We were lacking runners. Once we started to do other things, we made mistakes and that cost us a bit of belief. A shooting problem. If we don't shoot, they cannot be on target. If you play against a deep block like today, it's hard to take shots.
"We found the spaces, it wasn't easy. We had a lot of shots, but I think there are some chances late in the game where it wouldn't have been so hard to find the target."