Villarroel joined Cermaq in 1998 and held different financial positions in Mainstream Chile before he transferred to Mainstream Scotland where he worked as a financial controller. From 2005 to 2007 Villarroel worked as business controller for Mainstream Group. In 2007 he took over responsibility as managing director for the farming operations in Canada, and was appointed Chief Operating Officer Canada from November 2013. Villarroel is a financial accounting auditor with a degree in management.