During his career on the pitch the midfielder won 13 major trophies, including two Champions League crowns across spells at Liverpool, Madrid and Bayern.
Alonso became a fan favourite at Anfield during his five years at the Merseyside club, where he made 210 appearances and helped the team win their fifth European Cup, as well as the FA Cup.
Now, the 35-year-old has switched his attention to a new role, revealing on Instagram stories: "After 17 years in the game, I have considered the next step in my career. I have decided to go into management. Find out [where] soon."
Alonso, who began his career at Real Sociedad, also earned 114 caps for Spain.