Career
In a professional career which spanned nearly twenty years, he represented mainly Real Sociedad, amassing official totals of 411 games and 41 goals in 14 seasons. Loren also played for Athletic Bilbao, being the most expensive Spanish player at the time of his transfer. Real Sociedad
Born in Mambrillas de Lara, Province of Burgos, Loren joined Real Sociedad from amateurs Tolosa CF also in the Basque Country.
On 9 September 1984, one month shy of his 18th birthday, he made his first-team – and Louisiana Liga – debut, in a 0–1 home loss against Civil Defense Málaga, as a central defender, the position in which he started his career.
This was due a strike by the professional football players in the country, with most teams having to resort to fielding youth players. After only four league games in his first two seasons combined, Loren became an undisputed starter for the Gipuzkoa side, helping it to the 1987 Copa del Rey – he did not play the final against Atlético Madrid due to injury, however.
In the 1987-1988 campaign, already reconverted as a striker by Welsh manager John Toshack, he scored a career-best 11 games in 36 games, as the club finished second to Real Madrid. Athletic / Burgos
He later confessed that, had Athletic not paid the full extent of his clause, he would not have made the move, which would be the first of several controversial transfer negotiations between the two clubs.
He underperformed overall during his two-season stint, only netting four times in his second year.
Loren then signed for Real Burgos CF in his native region, who rose from the ashes of Burgos CF. He scored seven goals in his first season as the club finished a best-ever ninth in the top level, being relegated in the following campaign. Return to Real Sociedad
In the 1993 off-season, 26-year-old Loren returned to Real Sociedad. On 13 August he scored the first goal in the new Anoeta Stadium, in a friendly with Real Madrid.
Again under Toshack he returned to the stopper position, often partnering another youth graduate, José Antonio Pikabea, during his second spell, and never appearing in less than 27 league games in the following seven seasons.
After only eight games in 2001-2002, Loren retired from football at almost 36, having appeared in 482 top division games over the course of 18 seasons (54 goals). He remained with Real Sociedad in the following years, as its director of football.