Most football fans believe the Argentine should have the book thrown at him for refusing to play in a Champions League tie.
But former West Ham United teammate Mascherano insists City have handled things badly.
The ex-Liverpool star said: "Carlitos has done so much for Man City that I think it is so ugly what they are doing to him now. I can't believe what is going on.
"Everyone attacks him even when he can't defend himself. It's so unfair.
"But England is a complicated place, because when something like this happens, everyone attacks you."