In the UK there are many opportunity to improve his skills.
I saw a football summer camp in Manchester City!
It is a school share by Manchester City football team where the children could learn English and gain football skills during a two weeks programme. That could be very interesting for your 16 year-old son.
You can see more detail if you want, the programme is sold by trans world soccer: twsoccer dot com
This football summer holiday could be a beginin before let him go in a football school.
