I've answered this, but will do it again.
He wasn't fully fit, certainly for the PL when he joined. MoPo made that crystal clear.
Mopo knew and said as much openly after his first game for us, where he was so impressive that he needed time and greater fitness.
He got injured, he was forced to play and he knew it wasn't feeling right, he used laid down protocol of standing himself down when he knew - subsequently, a serious groin injury was diagnosed. Before then Jose basically called him a 'lazy ****' or as good as because he'd protected himself the way he was told to.
His teenage years were just that, teenage years, where he'd clearly put them behind himself at Lyon and became one of the hottest properties in Europe.
Jose has fcuked him over, no one else because of his own ego issues and his propensity to pick out players publically when his team isn't delivering - it's a distraction tactic he's used again and again - it's why he has a well-earned reputation in and outside of the game for 'chucking players under the bus'...
personally, I'd rather get rid of Jose and work twice as hard to save N'dombele - who with Gio would be one hell of a combination - the sort of midfield we desperately need.