The France international forward appeared to be edging towards the exits over the summer, as the Red Devils were heavily linked with a move for his services .
Griezmann was, however, to commit to Atletico as they served a transfer ban, with a new contract signed in the Spanish capital.
The 26-year-old has endured a dip in form since then, though, and a man who helped to put him on the path to stardom has suggested that a much-discussed transfer now appears to be on the cards.
Eric Olhat told French publication L’Equipe : “It’s a complicated situation for him but it feels like the end.
“I know him very well and we are still close, but to see him play at the level he has for much of this season means something is not right.
“Ok, he can change his mind of course and in football nothing is certain, but this feels like the end of his chapter with Atleti.”
That effort was, however, his first in eight outings for the La Liga giants.
At the height of his struggles, Griezmann was subjected to jeers by the Atleti support – with whistles raining down on him during a derby clash with Real Madrid.
Olhat believes that treatment could contribute to a departure, with a proven frontman having little to prove at the highest level.
He added: “He is very emotional, I am sure he took this poorly. He is a player who gives his all and doesn't try to cheat anyone even if he has a bad day.
“The attitude of the fans will have hurt him, even if he says otherwise.”