[2] In his playing career, Romeu was a defensive midfielder who spent two years in the youth sections of CE Europa, up to under-16 level, before joining amateur club CP Sarrià.

[2] In 2024 his former Sarrià coach compared his playing style to that of Keira Walsh, describing Romeu as a pivot with good vision but who rarely advanced,[3][4] even becoming "more aggressive defensively" as he progressed.

After a season, his dedication saw him named the assistant[4] to Sergi Milà in coaching the 2004 generation – including Gavi, Ángel Alarcón, Ilias Akhomach and Aleix Garrido – in their successive sections for the next two years.

Romeu worked in analytics and game preparations, with the club considering him important to the dominance they experienced under Giráldez,[9][10] winning ten of the twelve available trophies.

Romeu, noted for a strength in analytics and his strong relationships with players, was selected;[1][10] he was reported to have been internally chosen in February 2024,[11] and took over after the conclusion of the perfect 2023–24 season in June.