We have dropped some clangers at City RSC, Jo (70% of Hughes players) but Mangala will finish as our biggest mistake. Mangala has everything to be a top defender except the brain, Like Micah Richards before he got too big and slow. Good pace, agile for a centre back, strong and the way he dealt with Zlatan and a couple of brilliant performances against Chelsea CL shows he can defend when he gets it right and more importantly has to constantly defend so can't switch off. His problem is his mind and his absolute lack of positioning, constantly crossing over the other centre back all down to poor concentration and the final nail from Pep is he is absolutely useless with the ball.
I like the guy cause he gives his all. He's kind of like Richard Dunne, in a team where he's constantly under pressure, he'll probably look a great defender because he'll be surrounded by others, in a big team where your main requirement is to be switched on for the entire games and not get caught out of position to counter attacks he's found wanting. Its a pity because the potential was there but imho if he does end up a top defender it will 5-6 years before his mental game comes on, if it ever does.