Whilst at Varzim, Barros was noticed by the Portugal national team, and made his senior debut on 29 March 1987 in a 2–2 draw against minnows Malta for the UEFA Euro 1988 qualifiers, playing the second half of the match held in Funchal, Madeira. During his time with Juventus he was already a leading player, although he was unable to help his country qualify for the 1990 FIFA World Cup to be held in Italy.