Romero, at 15, became the youngest debutant in the LaLiga when he came on in defeat to Real Madrid on Wednesday night.
Romero was born in Mexico, where father Diego once played for Alacranes de Durango. The now 45-year-old former midfielder played for CD Olmedo and Técnico Universitario in Ecuador before crossing over to Spain with his family. After playing for a number of clubs in Andalusia, Romero senior signed for UD Formentera in Ibiza in 2011. That is how son Luka took his first steps on the football field at PE Sant Jordi.
Romero's talent caught the eye early, as at the end of 2011 he was invited at the age of seven for a number of trial training courses with Barcelona. The Catalans were charmed by the Mexican-born midfielder, but a FIFA rule prevented him from being added to the youth academy.
FIFA insists youth players at such a young age must live with their parents in the city of the club. Romero senior was still pursuing his career in late 2011, preventing the family from living near Barcelona.