According to The Sun, Gary's career as a soldier comes to a premature end when he is punished for attacking a policeman on a night out.
A source told the newspaper: "Gary is devastated when he is discharged from the army. He pleads with his CO but is told they have no option."
Gary returned from a tour of duty in Afghanistan last month, having been injured in a roadside bomb incident which killed a number of his colleagues.
Events took a new twist last week when the devastating tram crash on the cobbles triggered symptoms of post traumatic stress disorder for Gary, as he suffered terrifying flashbacks to his time in a warzone.
Mikey North - who plays the anguished character - recently confirmed that Gary's recovery will be a "slow process".