Ba did well obviously, but it was pretty clearly to the detriment of the team, it's what started Cisse's current life shitness.
Of course, that can also be aimed at the manager as he should have just shunted Ba to the left when it was pretty obvious he was gunna f*** off anyway.
Ba left in January last year though. I don't think you can blame the Ba factor for Cisse being shite over two halves of a season.