For all of the youth team age levels, you can go back a few years and struggle to find anyone playing outside of Spain. That's why Angelino, Maffeo and M Garcia don't have youth caps despite being the talents they are.
There's a video on an article from the MEN last year here: http://www.manchestereveningnews.co...-news/manchester-city-new-messi-diaz-10464255 which shows Diaz at a younger age. He's the little lad playing against older, much bigger lads and bamboozling them all (ferocious tackler too). The very last goal where he ties the goalie in knots is astonishing really.
Feel bad for those three, but hopefully if they progress under Pep they can make the step up. I was going to comment on Aleix Garcia having youth caps but realized we just bought him from Villareal.