Isla took part with Chile in the 2007 South American Youth Championship, where Chile qualified for the 2007 FIFA U-20 World Cup. During the U-20 World Cup Isla was noticed worldwide for his skill with the ball and versatility. Isla was an integral part of the team that finished in third place. In the quarterfinal game versus Nigeria, Isla played defender, midfield, and forward due to a number of injuries to other squad members. The game went into extra time after finishing scoreless in regulation and in the added time, Chile scored four goals. Two of the goals came from Isla, one from the penalty spot. After each goal Isla ran over to the Chilean telecast camera (which was marked by a Chilean flag) and dedicated his goals to his grandmother and aunt, who was pregnant. This tournament and his performance in it led Isla to be transferred to Serie A team Udinese before his professional debut in the Chilean league, a very rare occurrence.