sentences:  Born in Barcelona, Catalonia, Serrán was a product of RCD Espanyol's youth system.He appeared in three La Liga games with the team, his debut coming on 11 March 2007 in a 1–1 away draw against Racing de Santander; during his tenure at the "Estadi Cornellà-El Prat", however, he was mainly registered with the B-side.Deemed surplus to requirements following Tintín Márquez's appointment to the managerial post at the "Estadi Olímpic Lluís Companys", Serrán signed a three-year contract with Swansea City in the Football League Championship, with teammate Jordi Gómez also making the move on a loan deal.