City have made the attacking midfielder the most expensive English player of all time by spending £100m to extricate him from Villa Park.
Grealish has emerged as one of the best players in the Premier League, particularly outside the top six, and was inspirational at times for Villa last season as they finished 11th in the table.
Can Bailey replace Grealish?
In total, he scored seven goals in all competitions and registered 12 assists too.
But Hatfield believes that teams discovered that stopping Grealish last term essentially meant stopping Villa.
In preparation for his departure, though, Dean Smith’s side have been active in the transfer market and have brought in Emiliano Buendia from Norwich City, Leon Bailey from Bayer Leverkusen, and Danny Ings from Southampton, while also bringing in Axel Tuanzebe on loan from Manchester United and Ashley Young on a free transfer.
Hatfield said: “Under Dean Smith, with Jack Grealish in the side, despite his efforts to make sure that the whole team produces, a lot of people have looked at it and figured out that if you stop Jack Grealish, you can probably stop Aston Villa.
“Now it will be a different matter.”