On 20 November 2011, aged 17, he made his first team – and Primera División – debut, coming on as a late substitute in a 2–1 home win against Guaraní.

On 18 December 2011, in only his second appearance, he scored his professional goal by netting a last-minute equalizer in a 2–2 home draw against Cerro Porteño.

[8] He made his debut abroad fourteen days later, starting and scoring the only goal of the match in a Liga MX home win against Veracruz.

[11] On 24 August 2020, Domínguez was announced as the first Designated Player of the newly formed MLS franchise Austin FC, set to make its competitive debut in 2021.

[18] After playing for Paraguay at under-17 and under-20 levels, Domínguez was first called by the full side on 2 October 2014, for friendlies with South Korea and China.