Speaking to PokerScout, Barnes said of Grealish: "He's won everything, so I don't know how harmful it is, in terms of being a regular player every single week. Jack is a bit of a maverick, so when he's at Aston Villa he did whatever he wanted, played wherever he wanted, he went and dribbled around the goalkeeper, he could do anything.
"At Man City, he was more of a disciplined player. And as much as he did well, he played on the wing when he got the ball, but he's held his position. He didn't wander everywhere to get the ball and maybe that's who Jack is. Maybe he has to be at a club whereby he's the number one person who's given a free role to do what he wants.
"He's not going to get that at Man City. So as much as he won everything at Man City, he was probably more influential at Villa than he was at Man City. As to whether he's happy, being a bit part player at Man City, I’m not sure."