Gago was part of the under-20 squad which won the 2005 FIFA World Youth Championship and was one of many touted "future stars" in the competition. Though he was not named in the squad for the 2006 World Cup in Germany, he made his debut a year later and played in the 2007 Copa América. Since then, he has been a regular squad member. He was part of the team which won the gold medal at the 2008 Olympics. Although he was often in the starting line-up under Diego Maradona, he was not included in the squad for the 2010 World Cup, but returned to Argentina's squad for the 2011 Copa América.