Hart, who has 348 appearances for City, was sent out on loan to Torino this past season after new manager Pep Guardiola deemed him surplus to requirements, instead signing Barcelona keeper Claudio Bravo.
Bravo had an underwhelming debut season at the Etihad, and Seaman believes Hart would be happy with the way things have panned out.
"Joe will have been having a right little giggle to himself looking back and watching Manchester City," said Seaman via the Express.
"As much as he loved City, when somebody says that you are no longer required at the club, that's a massive blow.
"It's like when I was turned down by Leeds as a youngster. I was told I wasn't good enough. It was a long time ago but it is the same thing. Somebody is saying about your talent and your ability, 'No, I don't want that'."