Martin Demichelis does not know why Manchester City have shipped so many goals in the Champions League group stage.
The reigning Premier League champions have recorded just two points from their first four Group E outings and have only scored four times whilst conceding on six occasions.
A 2-1 loss to CSKA Moscow a fortnight ago has been the lowlight but Argentine centre-back Demichelis feels the entire defensive effort simply has not been good enough from Manuel Pellegrini's men.
"It is difficult to say why we have conceded so many but after every game we analyse it and what happened. Some of the games are down to bad luck and some down to errors," he said.
"In the last match we controlled the game and I don't think they had more than three chances, so I think we were a bit unfortunate to concede."
City will get the chance to improve their defensive output when they host German champions and group leaders Bayern Munich at the Etihad Stadium on Tuesday night.
