Sergio Duarte has said he would like to play for the US U-20 team this cycle. He's already made his Portguese Primeira Liga debut with Nacional this season. He signed a three year deal with Nacional this past summer. Here's an interview with Duarte. http://www.yanks-abroad.com/content.php?mode=show&id=9582
I'm always leery of the players who just sort of happen to be born here, but he seems to be saying all the right things.
Well spotted -- updates should probably go here at this point: https://www.bigsoccer.com/threads/sérgio-duarte-at-cd-nacional.1975022/