His first assignment with the US Soccer Federation was working with the U-18 United States. Barrieu was then named the United States strength and conditioning coach for the 2002 Gold Cup, where the USA won their first Gold Cup in 11 years. Barrieu went on to coach for the United States in the 2002 World Cup . In particular, the fitness of the USA team was widely believed to have been an important factor during the historic run to the quarterfinals in Korea.