Guti has left a youth coach role at Real Madrid and will join Turkish club Besiktas as assistant to manager Senol Gunes.
Former Madrid player Guti was reportedly considered as a candidate to fill the vacancy left by Zinedine Zidane's resignation as coach, but Julen Lopetegui was appointed.
After two years with Madrid's Juvenil under-18s side, the 41-year-old had been linked with managerial roles at Leganes, Segunda Division Murcia and Scottish club St Mirren.
Guti, who spent the final season of his playing career at Besiktas in 2010-11, said in a statement published on his Twitter account: "Today I want to thank Real Madrid, my home, for all the years I enjoyed as a player and as a coach.
"In a few days I am joining Besiktas, my home too, as assistant coach to continue my professional development. I thank Besiktas for the affection and confidence they have put in me, and I will return that with a lot of work and motivation."
Guti scored 77 goals in 542 games for Madrid between 1995 and 2010, winning five La Liga titles and three Champions League trophies.
His replacement as U18s coach is expected to be Dani Poyatos, who left a role in the Bernabeu youth set-up last season to work as an assistant to Jordi Cruyff at Maccabi Tel Aviv.