In the 2005–06 campaign, Castedo appeared in 33 league contests, also playing in all of the season's UEFA Cup matches as Sevilla lifted the trophy against Middlesbrough – 11 of those were complete. In the following year, due to the emergence of youth graduate Antonio Puerta and the consolidation of Ivica Dragutinović, he appeared less, but still managed 26 appearances overall, including seven in the UEFA Cup as the club renewed its European title.