Villarroel began his football career at the youth ranks of hometown club Blooming at age 10. He made his top flight debut on May 26, 2013 during a league match against Petrolero under manager Néstor Clausen. During his spell at Blooming he had 20 appearances in the Liga de Fútbol Profesional Boliviano and scored one goal.
Due to his impressive performance at such a young age, in July 2015 he signed for Universidad de Chile.
In March 2015, Villarroel participated with the Bolivian national team in the South American U-17 championship in Paraguay, but the squad did not qualify to the Fédération internationale de football association U-17 World Cup held later that year.