Considering we are supposed to be short of money for this season I would think of selling him while he still has a decent price, I must admit I have real doubts about whether he will make it or not, use the money to buy a better player after all at this time I don't think he would be missed.
Who's going to pay £20m+ for him? Nobody. Right now makes more sense to keep him in the hope that Ancelotti can get the best out of him.
It's been a disastrous year for everyone, not least for a 19 y/o lad that doesn't speak the language and moving away from home for the first time. Deserves time.