The Blues have let in six goals during their last two games as well as conceding in just 13 seconds earlier this month to Southampton, but bid to claim top spot of Champions League Group E by beating Steaua Bucuresti at Stamford Bridge on Wednesday night.
"As a defender, you're always worried when you concede a goal," Ivanovic told the press. "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."
You can enjoy live coverage of Chelsea against Steaua Bucuresti on Sports Mole tonight from 6.45pm.