Chelsea defender Branislav Ivanovic cannot explain their poor defensive record this season.
Chelsea have already conceded more goals in the Premier League this term than in the whole of Jose Mourinho's first campaign as the club's boss, in 2004/05.
"As a defender, you're always worried when you concede a goal," Ivanovic said.
"It's always important to not concede a goal and to keep a clean sheet. This, game by game, gives confidence for defenders and gives the stability for the team.
"For us as a defence line we will do everything to not concede a goal and try to do our best.
"In some goals we lost concentration. We conceded a couple of goals from set-pieces as well which is not usual for us.
"We know how strong we are in that part and we just have to get back to normal.
"We change a lot of small things for every game depending on the opponent. All these things have to work perfectly to not concede a goal."
