.....but why has City's central defender situation not been addressed so far?

Bamba and Morrison is the obvious first-choice pairing - with Manga and Connolly as replacements.

Both B and M were injured for a few games last season - and we struggled without them. Connolly wasn't great in the Premier League last time round (and I doubt he has improved ) and can you imagine Manga facing Kane/Aguera/et al ?

Suppose either B or M picked up a serious injury......