The two had worked together at Swansea and big things were expected from the Dutchman, who won Nottingham Forest's Player of the Year award the season before signing on at Celtic.
However, things didn't work out as de Vries quickly lost his place to Craig Gordon. Worse was to come when Scott Bain arrived in January 2018 and also managed to usurp him in the pecking order.
He didn't play a single minute of first-team football last season before his contract expired.
Having weighed up his options he's now decided to focus on his studies and coaching badges.
He wrote on Instagram: "After 20+ years as a professional footballer it is time for me to hang up my boots and gloves.
"I would like to thank all of u who supported me on this fantastic journey i had as a professional football player.
"I am very fortunate to have played for some fantastic and well supported clubs and i would like to thank everyone who worked closely with me, my family and friends, my former teammates, my agent, management, coaches, backroom staff and supporters at Telstar, ADO Den Haag, Dunfermline, Swansea city, Wolves, Nottingham Forest and Celtic.
"Now its time for a bit of a break but after holidays i will continue to work on my coaching badges and will start a master in sport management at the Johan Cruyff university which is something i am very excited about."