His career was going brilliantly, hevwas a 'hot property' around Europe & soon out of contract. We promised him first team squad, if he signed for us, rather than one of the top clubs who were hunting him. He did, then we shat all over him & he ended up sitting around waiting on last minute loan deals.
After that, he never really figured as a likely City player & this incident happened during that period. He ended up shit, in a shit Sunderland team & has somehow got his career back & is climbing the ladder again.
It was a little bit more complicated IIRC.
Summer 2015, Demichelis was supposed to be moving to River Plate, he had his bags packed and everything, and Denayer was going to replace him in the squad.
Meanwhile Negredo wantsed to leave because he's fallen out with Pellegrini. Valencia can't afford to pay for him, but they have Otamendi. The plan was for Otamendi, Mangala, Kompany and Denayer to be the 4 CBs.
At the last minute the Demichelis deal fell through. The club tried to offload Mangala on loan to a few Spanish clubs but he refuses to go anywhere after just 12 months.
In the end, the club decides to keep Demichelis for his last year and sends Denayer on loan again, this time to Galatasaray.
This essentially ends the relationship between Denayer and Manchester City. The next year he comes back and doesn't want anything to do with the club, who in turn refuse him another loan to Galatasaray as they want to test him in the PL and he goes to Sunderland begrudginly.
Then the summer after City want to sell Denayer, but they will only sell him with a buy back clause that's the same as the sale price, so no one will touch him. Lyon want him, but won't agree to such a stupid clause and he refuses to go to Girona because he's a CL quality player. Eventually the club send him to Galatasaray again as a compromise and he wins the league there before going to Lyon for £5m with no buy back.
I think there's an element of bad luck involved - he'd be a City player now if not for the River Plate move falling through for Demichelis, but at the end of the day...Pellegrini was allowed to take a short term position against the long term development of a club trained CB.
I don't think he'll ever come back.