The Chelsea duo of Kurt Zouma and Radamel Falcao have admitted instant improvements are required to keep the side's Premier League title defence on track after a surprisingly slow start to the season.
Crystal Palace's shock 2-1 win at Stamford Bridge on Saturday left Chelsea with just four points from their opening quartet of matches and eight points behind leaders Manchester City.
Zouma, 20, started in Saturday's game in the absence of the suspended John Terry and was absolved of blame for the defeat by boss Jose Mourinho after the match, as he hailed the performances of the Frenchman and his defensive partner Gary Cahill.
Yet Zouma accepts a collective responsibility for Chelsea's poor start to the campaign and has hinted they are struggling to come to terms with their status as champions.
"The season after we are champions, it's really difficult to prepare ourselves," he told Chelsea TV. "To improve is more difficult, but we have to improve ourselves and keep going, keep working. Mentally we have to improve.
"We are very disappointed with the result. The target was to win the game to confirm the win last week. Crystal Palace played well and we congratulate them, but we have to think about the next game now.
"We have a little break of two weeks and we have to recover very well and then come back stronger."
Falcao's first goal for Chelsea was quickly forgotten after Crystal Palace recorded a famous win at Stamford Bridge, with the Colombian striker accepting his new team needs to find their winning touch quickly.
"We are disappointed with the result and now we have to look forward and improve quickly," Falcao told Chelsea TV. "I'm pleased with my first goal for Chelsea, it was very special, but the result is more important.
"We didn't play as well as we wanted. We thought we could win this game. The manager has talked with us and told us some things where we can improve. We spoke in the dressing room. We have to improve."
Chelsea face a trip to Everton in two weeks' time, before they welcome London rivals Arsenal to Stamford Bridge in two games that could be crucial to their hopes of staying in touch with Manchester City.