Ivanovic and Ramires are two big losses Chelski would have to cope with - a lot more so than Terry and Meireles - but they managed to stop Barca with one single CB on the field, while having Cole and Bosingwa play in the center of defense too ... a game, common sense tells us they should have lost by 5-6 goals.
what I am saying is that it's the group effort that counts and if Chelsea manage to recoup a decent pair of CBs instead of having to conjure one out of thin air, they are a team to be reckoned with.
Bayern will also have their absentees to deal with albeit their issues aren't as big as Chelsea's