I don't know, I think it's facile to point to the Manager and talk about clubhouse issues. This Chelsea team really struggled for form in the 2nd half of last season but City were too busy throwing up on themselves for it to matter. The margins for last season's Chelsea team were very fine, they had an incredibly knack for finding goals when they needed them and Hazard had the team on his back for quite some time. I'm not sure that i'd write up any subsequent regression (either to the mean or complete loss of form) as morale issues as much as just the unsustainability of what the team did last season. It's also incredibly hard to defend a title and when things go south they can really snowball on you. It's not hard to see (to me) how all 3 of those things could conspire to create some ugly results for Chelsea.