Can the U.S cap him to prevent him from ever playing for us? Maybe but maybe the precedent has been set by the records of the following list of US players in Spain? Except for Lagos' measly three caps
Internationals in Spain:
Tab Ramos (Figueres D2, 1990-92; Real Betis D2, 1992-95),
Peter Vermes (Figueres D2, 1991-96)
Manny Lagos (Lleida D2, 1992)
Kasey Keller (Rayo Vallecano, 1999-2001)
Ante Razov (Racing Club de Ferrol D2, 2000-01)
Jozy Altidore (Villarreal, 2008-2011; Xerez D2, 2009)
Carlos Bocanegra (Racing Santander D2, 2012-13)
Oguchi Onyewu (Malaga, 2012-13)