I don't think he needs to work on his finishing, he doesn't lack anything from a specific technical standpoint and he won't improve his composure in training, it'll improve on it's own with confidence.
What worries me right now is how unbalanced he looks in everything he does, he lacks the agility of even ordinary footballers. When he breaks into a full sprint he looks close to falling over, every time, no chance of controlling the ball properly like that.
I hope it's because he's got a tad taller and a lot stockier since he broke his leg and it will take him a little time to adjust to that - time for his legs to catch up and give him a stronger base for his bigger frame.