Cristian Molano

Castells was born in Sueca, Valencian Community. An unsuccessful youth graduate of Valencia CF, he spent most of his career in the Segunda División B, also having Segunda División spells with Polideportivo Ejido and Alicante CF, both ended in relegation. Midway through the 2012–13 season, at already 28, Castells had his first top-flight experience, when he signed for Platanias F.C. in the Super League Greece. In January 2014, however, after only six competitive matches, he returned to his country and his native region, joining amateurs CF Cullera. Castells rarely settled in the following years, representing Spanish amateur clubs and professional teams in Romania (Liga II) and Northern Ireland. Early into the 2018–19 campaign, he served as manager of CF Torre Levante in the Tercera División.

Castells' younger brother, Marc, was also a footballer. A midfielder, he also represented Poli Ejido, but spent the vast majority of his career in the lower leagues.