Chelsea manager Antonio Conte has admitted that his players are having "problems" coping with the demands of the season.
In the Blues' Premier League title-winning campaign in the 2016-17 season, Conte's men did not have any European commitments.
This term, the West London outfit, who have won the English crown six times in their history, are competing in the Champions League, as well as the EFL Cup and FA Cup.
On Saturday, Chelsea were stunned in a 2-1 defeat to Crystal Palace, who prior to the match at Selhurst Park had not won a game or scored a goal this season.
"We mustn't be happy," Conte told reporters. "This season will be very difficult for us. For this reason we have to put 150% in; 100% won't be enough. I have players with a great will to work and fight. For sure we have to find the strength to overcome this moment. Everyone can see our situation.
"I think every season is different. Last season is the past. Now it is another squad, different players and for this reason if we compare last season we didn't play Europa League or Champions League. This season we are facing four competitions and we are having a few problems doing this. When you have a few injuries, you are in trouble."
Chelsea currently sit fifth in the league table, nine points behind leaders Manchester City due to four wins, one draw and three defeats.