On 20 July 2011, Tiago signed a permanent two-year deal. He was again an important part of the team that reached the Europa League final, usually playing as a starter under coach Diego Simeone, who replaced Gregorio Manzano midway through the season; he missed the decisive match in Bucharest however, being sent off in the semi-final's second leg against Valencia CF (1–0 away victory, 5–2 on aggregate) after slapping Roberto Soldado.