“It has been an amazing three years back home at Real Sociedad,” he wrote. “Thanks to Jokin, Roberto, the staff and all the players who have helped us to improve and enjoy this intense adventure so much. Aupa Sanse and Aupa Real!”
He took charge of 98 matches during his time in charge, overseeing 40 wins, 23 draws and 35 defeats. He used 51 players during his reign.
Where Alonso goes next is unknown. He was a hugely successful player, representing La Real, Liverpool, Madrid and Bayern Munich with distinction throughout his 18-year senior career.
He was also a key part of the golden generation of Spanish players who won Euro 2008, the 2010 World Cup and Euro 2012.
After three years working with a second string and learning the ropes of coaching, Alonso will be keen to land himself a first-team position this time around. His next job is going to be pivotal.