Under-23s: Called into the U-23 MNT in November 2011 for a camp in Germany and played in a friendly against Azerbaijan … Under-20s: Heading into the 2013 FIFA U-20 World Cup, Villarreal scored a team-leading five goals in seven games. Villarreal was named to the CONCACAF U-20 Championship All-Tournament team as the USA took second place. He was the USA's leading scorer in that tournament with three goals, including two goals during the 4-2 quarterfinal victory against Canada on Feb. 26 to book a World Cup spot. In 2012, played in four matches and started three times while tallying three goals … Under-18s: Played for the U.S. Under-18 National Team at the 2011 Milk Cup in Northern Ireland in July, tallying one assist while starting all three games at the tournament.
The LA Galaxy homegrown player made his debut on the first team roster on July 14, 2012, as a substitute during a 5-3 win against the Portland Timbers. Villarreal scored the first MLS goal four days later on July 18, 2012 – an 87th-minute equalizer for a 2-2 draw against the Vancouver Whitecaps. He had two goals and an assist in 14 games in his first MLS season.