Former Spain midfielder came through the youth ranks at the club.
Former Liverpool and Real Madrid midfielder Xabi Alonso has been appointed as the new head coach of Real Sociedad's B team.
The former Spain international signed a two-year deal with his boyhood club, where he made 124 appearances before joining Premier League cub Liverpool back in 2004.
Alonso has now joined Sociedad from Los Blancos, where he spent the season working as a youth coach.
He replaces Aitor Zulaika, who has been relieved of his duty.
A statement on Sociedad's official website read: 'Real Sociedad have reached an agreement with Xabi Alonso to be head coach of Sanse for the next two seasons.
'The Tolosa-born coach, who joins from Real Madrid, returns home to be in charge of the txuri urdin reserve team.
'Aitor Zulaika will not continue as Sanse's head coach. Sanse's new technical staff will be announced in the coming days.'