[4] On 29 August 2007, just two days before the close of the transfer window, Italian club AS Roma obtained the player on a loan deal for €300,000, with the option to buy him permanently open until 15 April 2008.

[8] He also started against the same opponent in the semi-finals of the Coppa Italia in April, which ended with another victory at the Stadio Olimpico (1–0),[9] but was, however, virtually absent in the league, being barred by Italian internationals Marco Cassetti and Max Tonetto and totalling only 65 minutes of action.

[10] On 2 April 2008, Roma exercised their right to full ownership, paying Paços de Ferreira the sum of €1.2 million whilst the player signed a five-year contract.

[2][15] On 31 January 2011, Antunes was signed by A.S. Livorno Calcio along with teammate Marco D'Alessandro on loan, with Roma paying the player an incentive of €270,000 in order to compensate the wage difference between the two clubs.

[19] He made his La Liga debut on 9 February, playing the full 90 minutes in a 2–1 away win against Levante UD,[20] and participated in 15 official games during the season, including four in the Champions League.

[21] On 2 February 2015, Antunes made a deadline day move to Ukrainian Premier League club FC Dynamo Kyiv for a reported fee of around €6 million, signing a four-and-a-half-year contract.

[32] Antunes represented Portugal at the 2007 FIFA U-20 World Cup in Canada, playing all the games in an eventual round-of-16 exit and scoring in a 1–2 group stage loss against Mexico.

[35] On 10 October 2017, he played 22 minutes in the decisive 2–0 home win over Switzerland for the 2018 FIFA World Cup qualifiers to help the nation top its group,[36] and he scored his first goal on 14 November of that year in a 1–1 friendly draw with the United States.