[4][5] In July 2005 he returned, going on to be an instrumental element in the team's midfield (alongside Raul Meireles and Lucho González) as they eventually won three consecutive league championships.

[6][7] Assunção left the Estádio do Dragão after being threatened with a shot to the knee by Porto supporters who wanted him to renew his contract.

[9] He adjusted quickly with the capital side, playing all La Liga matches safe four and helping them repeat the fourth-place finish, with a subsequent qualification for the UEFA Champions League.

[10][11] Defensive-minded Assunção scored his first goal for the Colchoneros on 17 January 2010, during the team's 3–2 home win against Sporting de Gijón.

[14] The deal was confirmed on 21 July 2012[15] but, on 28 December, it was terminated by mutual consent,[16][17] with the player returning to Spain and joining Deportivo de La Coruña.