Born in Inglewood, California, Villarreal started his career at the LA Galaxy academy set-up. While with the U18's Villarreal scored ten goals as he led his team to the Southwest Division championship. In 2014, he signed his first professional contract with the LA Galaxy II, the reserve team of the LA Galaxy, of the USL Pro. He made his debut for the team on June 8, 2014 against the Dayton Dutch Lions. Villarreal came on as a 58th minute substitute for Jack McBean as the LA Galaxy II won 5–1.