Chelsea boss Antonio Conte admits his players lost their cool as they were reduced to nine men in a shock 3-2 Premier League defeat to Burnley.
The champions suffered their first opening-day loss for 19 years after failing to recover from a first half that saw Gary Cahill sent off before Burnley raced into a three-goal lead, courtesy of Sam Vokes' double and a superb Stephen Ward strike.
Alvaro Morata almost inspired a comeback as a second-half substitute, scoring before setting up a late strike for David Luiz, a goal that came after Cesc Fabregas' removal for a second yellow had seen Chelsea reduced to nine men.
Conte was proud of the second-half effort, but acknowledged Chelsea lost their heads after Cahill saw red, a period in which Fabregas got his first booking for sarcastically applauding referee Craig Pawson, who came under pressure from the home players and supporters.
"The sending off of Cahill was a key moment, because to play the rest of the game with 10 and then nine men is not easy," Conte told Sky Sports, referencing the FA Cup final and Community Shield, when Chelsea also had players sent off.
"In the last three official games we have finished with nine or 10 men. I have to try to adapt a new system and to anticipate this situation of playing with nine or 10 men in the next game.
"I don't want to comment on the referee, absolutely not. We tried until the end to reach a good result against Burnley - it was a pity because our fight in the second half was very good.
"But our first half we kept losing our heads - after the red card we lost our heads a bit, conceded three goals and then it's very difficult to change the final result.
"We must focus on working very hard with these players. As for the transfer market, the club is trying to do the best. I am not worried, I am ready to fight with these players.
"I repeat: it is important for us to be concentrated on our work, to be focused every day in training and to try to work in our best way. No excuses."