Jose Mourinho has revealed Chelsea have concentrated on defensive work ahead of the club's London derby with Crystal Palace on Saturday, with the champions yet to keep a clean sheet this season.
The Blues have conceded seven goals in their three league games so far this term, meaning Chelsea have failed to keep a clean sheet since their post-season win over Sydney FC in June.
Chelsea have also had to play out two games with 10 men after goalkeeper Thibaut Courtois was sent off in the 2-2 opening-day draw with Swansea City while captain John Terry saw red for his foul on Salomon Rondon in the 3-2 away win against West Brom on Sunday.
With Alan Pardew's Palace side having scored six goals in their first three games, Mourinho has revealed he has made sure his Chelsea team have focused on defensive work in training this week - and in particular, defending with nine men.
"We have worked on a few things on defending in training, such as defending with nine men," the Portuguese tactician said on Friday.
"We also worked on tactical aspects to improve the team. I didn’t just work the defenders, I worked the team because you have to defend as a team.
"You cannot blame defenders for goals conceded because a team is a team and good one defends as a team."
Chelsea beat Palace in the corresponding fixure at the end of last season, a victory that clinched the Premier League title for the Blues.
But Mourinho is expecting the Eagles to provide tougher competition at Stamford Bridge on Saturday, although he remains confident his team can secure all three points.
"This is a different match but with the same need to get the three points," Mourinho said.
"Last season was to win the title, this season it is to try to recover positions we lost with two bad results at the opening of the Premier League.
"Crystal Palace are always a difficult opponent and they have even better players than last season and an even better team than last season. A London derby is always a London derby and for them Stamford Bridge is a huge motivation.
"But I see my team coming and we had a good game and good result last weekend.
"That result had a bit of an influence on the happiness of the group and hopefully we can get three more points before the period of international games."
