The 26-year-old had looked set to complete a world-record switch to Old Trafford earlier this summer, only to change his mind after it was confirmed that the La Liga side's transfer ban would remain in place.
Now agent Olhats has revealed that he has parted ways with the footballer, having represented him since the age of 14.
"The recent positioning of Griezmann's image and future is no longer in harmony with our vision as a partnership," he told L'Equipe. "I will focus on my role as a Real Sociedad scout.
"I thank [Griezmann] for his confidence in me over the course of various years. Obviously I wish him the best in the next chapter of his career."
Despite signing a new deal with the capital outfit, Griezmann has admitted that he could still move on next summer.