Thiago Silva admits he is worried by Paris Saint-Germain's form following their 2-0 loss to Toulouse on Friday.
Goals in the second half from Yann Bodiger and Jimmy Durmaz consigned the Ligue 1 champions to defeat, after Serge Aurier had been sent off for two yellow cards.
PSG have now lost twice in their opening seven Ligue 1 matches - they only suffered two league defeats in the entirety of last season - and they could be four points behind leaders Nice should Lucien Favre's side beat Nancy on Sunday.
Thiago Silva felt Toulouse were deserved winners and concedes that PSG's struggle to find form under Unai Emery has been something of a concern.
"Yes, it was difficult, it was not a good match for us. We didn't manage to play, to find the spaces. They deserved to win," he said.
"It's not usual to have two defeats like that, but that's football. We have to stay calm.
"What worries me a bit is that we lost some of our game. I think that, gradually, it'll come back.
"Last year we started the season well and finished it better. This year we haven't started well, but the season is long. You have to think as a team. For now, we have to think about how we can change things."
Emery questioned the decision of referee Frank Schneider to issue a second yellow card to Aurier when he conceded the penalty for a foul on Ola Toivonen, but Thiago Silva refused to blame the officials.
"It's hard to stand here and talk about referees, et cetera," he said. "It's difficult to talk with them, but that's not an excuse. Toulouse had a good game and we didn't play well, but we know we can do better."