Thomas Tuchel has admitted he had a strange feeling in the dressing room before PSG's 2-1 home defeat against Manchester United in the Champions League on Tuesday.
The Red Devils took a first-half lead at Parc des Princes as Bruno Fernandes scored from the spot after his original penalty was saved by Keylor Navas, but was then ordered to be retaken due to the goalkeeper's encroachment.
Anthony Martial's own goal in the second half levelled the match, but Marcus Rashford scored a dramatic winner in the 87th minute to help lift the pressure on manager Ole Gunnar Solskjaer.
In his press conference after the game, PSG manager Tuchel said he felt his side were "a little too calm" ahead of their Group H opener.
"The mood in the locker room was a little too calm before the game," Tuchel said. "I had a weird feeling. Usually we listen to music at a very loud volume. I had the impression that it was too calm.
"As for half-time, it was not the time to be angry. We had to improve, but we clearly said that we lacked intensity and aggressiveness. It was necessary to show another attitude."
Speaking to RMC Sport, Tuchel said that he hardly recognised the team that he saw on Tuesday after winning five straight Ligue 1 matches.
"We missed a lot of things, offensively and defensively. It was not a match at our level, not at all, whether in the offensive or defensive phases, technically, tactically, in our intensity and against pressing," Tuchel said.
"It wasn't us, clearly. Now is not the time to be mad and lose our mind. We have to be very honest with ourselves and be critics as always. It was a very hard start for us."
Tuchel added that he was hoping his side could control the match better at home, but Solskjaer's men made that task too difficult for them.
"We lacked rhythm and intensity," the German said. "We were nevertheless well prepared.
"[Am I] angry? No because these are the same players who have done good things in the last games and months. It was difficult today, I don't know why but that's how it was.
"It wasn't difficult to play a better second half [than first half], but it was too open. We didn't have the capacity to control the game."
PSG defender Presnel Kimpembe echoed his coach's disappointment that his side weren't in top gear on Tuesday.
“There's no explanation, we just weren't good," Kimpembe said. "We weren't in the duels and were behind on the defensive run-backs.
"We can only blame ourselves. We weren't surprised by their starting XI. It's just that we weren't good. We didn't approach the game well, and did not finish it well. It's a shame to lose points like that, we'll have to chin up."