Didier Drogba accepts Chelsea cannot continue to give teams the 'belief' they can get the better of the Premiership champions.
In the continued absence of goalkeeper Petr Cech and skipper John Terry, who could face an operation on his recurring back problem, the Blues have looked somewhat shaky in defence.
Over their last three Premiership matches, Jose Mourinho's men have leaked six goals - a trait which proved costly against Reading on Boxing Day at Stamford Bridge, where the 2-2 draw saw Chelsea loose ground on leaders Manchester United.
Drogba said: 'It is something we have to think about. We cannot give the other teams the belief that they can score, that they can win.
'Last season, and also two years ago, we were very strong when we scored one goal and they other teams could not think about coming back into the game,' the striker told Chelsea TV.
Chelsea have now let in 15 goals - only seven less than they did over the the course of the whole of Premiership campaign last season.
Having sold both William Gallas and Robert Huth, Mourinho admits the continued absence of the England captain has left him short of options in the centre of defence.
The Chelsea manager has even considered asking 19-goal striker Drogba to step into the role on an emergency basis.
The 28-year-old said: 'I do not like to play at centre-back - but I do it for the team because sometimes we have difficult moments in the game.'