The Alianza de Futbol folks say: Julio César Morales (SJ), David Silva (SJ) and Erick Venegas (PHX), were discovered by Alianza de Futbol, but now they play for Guadalajara's youth categories. http://www.alianzadefutbol.com/site/noticias-noticia.php?id=109&filtro= In any case, Venegas appears to be a '94 named Erik Alejandro Venegas Baca. The Mexican Fed says he was born in Mexico, but of course he could still be American. (Morales I already knew about. Still trying to find out more about Silva.)
According to MLSS he was born in Phoenix and was on the Chivas U17 championship team last year. http://www.mlssoccer.com/news/article/2012/07/12/gringo-report-four-young-americans-watch-mexico