He played 67 games in Segunda División, winning promotion with Mallorca (1997), Real Murcia (2003) and Recreativo de Huelva in 2006, despite not being first-choice in any of those campaigns.

[1] Released by Córdoba in 2004, but still training with the club, Valero moved abroad for the only time as a player in January 2005, to sign a one-month non-contract deal with Wrexham in Football League One.

[2][3] He made two more league appearances for the Red Dragons, as well as a 2–1 win in the FAW Premier Cup quarter-finals away to Haverfordwest County on 18 January, and shared teams with compatriot striker Juan Ugarte.

[5] After José Ochotorena decided to return to Spain to work with Valencia, Rafael Benítez appointed Valero head goalkeeping coach of Liverpool in July 2007.

[5] He was praised by Liverpool striker Fernando Torres as one of the biggest reasons for his goals; during training, he instructed the players on how goalkeepers in future games react to one-on-one situations.