Jose Mourinho will demand his leading players, including Eden Hazard, improve after Chelsea's chastening start to the season.
The Barclays Premier League champions have four points from four games and sit eight points behind leaders Manchester City after Saturday's 2-1 loss at home to Crystal Palace.
It was Mourinho's second loss in 100 home league games as Chelsea boss and he was frustrated by individual and collective performances.
He would not name names, but there was implied criticism of even Hazard, who dazzled in the title-winning season.
"If you are the best in the Premier League, I think it should be a good responsibility to have a similar season as in the previous season," Mourinho said.
"I don't want to analyse individual performances. When you have six or seven performing and three or four who are not (at) an acceptable level, it is difficult for a team to be consistent in the performance."
Others whose form has dipped this term include Branislav Ivanovic and Cesc Fabregas - and Mourinho vowed not to accept the downturn.
Whether he turns to the transfer market in search of answers ahead of Tuesday's 6pm deadline remains to be seen.
Mourinho said: "If you ask me, will I accept this, cross my arms, sit in a nice chair and wait calmly for the performance level to be back? No.
"I have to work, I have to react, I have to analyse and if I feel the players are not in conditions to react and give more, I have to make changes. I have never had a problem with that."
Chelsea are bidding to be the first team since Manchester United in 2009 to retain the Premier League title.
While for some winning once might be enough, Mourinho is a serial winner and will demand the same of his players.
"If you win it once and the next year you are not on fire, or you are not ready to at least fight for more, that is sad," he added.
"When I win, I want to win again, I want to win more. I feel fantastic motivation for more."
Palace boss Alan Pardew had recognised Ivanovic's poor form.
It was a deliberate ploy to target Chelsea's right flank and when the effectiveness of the tactic waned a little, on went Yannick Bolasie.
"We doubled up on a him a little in the first half, with Sako and Wilf (Zaha)," Pardew said.
"(It) worked for us for a little bit, then it didn't. Yala (Bolasie) came on and I didn't think he (Ivanovic) got much protection."
Bolasie was playing after missing two games following the death of his father.
"He contacted me on Thursday, (said) that he felt that he could play," Pardew said.
"I decided not to start him. It was a big boost for us to have somebody like him poised to come on.
"He obviously made a big difference when he came on."
Bolasie has been linked with a move this summer, with Tottenham reportedly interested and Pardew slapping a £25million price tag on the winger.
"Yala is a big part of my plans," the Palace boss added.
"It will take an unbelievable offer to get him out of here. If someone wants to make that we'll listen."