While true, JG is mentally fragile, so I don't think you go that route with his type of personality/mentality. You tell him you are 110% behind him and to go BALL THE EFF OUT.
He gets pulled the same in either scenario, but you can't have him focused on making mistakes. That's when he sits on routes too long, gets in his own head, and actually makes more mistakes. Like a self-fulfilling prophecy.
You have to release his mind. Just like "under pressure" and on 3rd downs. You have to get him out of his mind, whatever it takes. That's when he's at his best.