He looks like he has talent but he has that kind of Bily/Ozil gait which means when the team isn't playing well he's usually the one hooked as it appears he's not grafting like the rest.
ETA: just had a look on their fans forum, they're not too impressed with him overall. Too lightweight it seems and doesn't deliver enough every week.
This is where having the right manager will aid his development. Someone like Martinez would tell him he’s the next Zico and to go and express himself and just fanny about all game, looking for through balls. Whereas Poch took Dembele and Ericsson (who were both seen as luxury players and had fitness issues) and turned them into solid, tactically and positionally astute pros - without crushing the flair out of them.