On 26 April 2017, Seoane extended his contract with Los Blancos until 2020.[3] He scored his first goal for Castilla on 1 November, scoring his team's second in a 4–1 away routing of Celta de Vigo B.[4]
On 31 January 2020, after appearing rarely, Seoane was loaned to fellow second division side CD Lugo, until June.[9] Upon returning to his parent club, he made his La Liga debut on 13 September, replacing Mikel Rico late into a 1–1 away draw against Villarreal CF.
On 1 July 2022, free agent Seoane signed a three-year contract with Getafe CF in the top tier.[10] On 4 August of the following year, after being sparingly used, he signed a one-year deal with second division side Real Oviedo.[11]