Former Manchester United keeper Foster admits Hart had only positive comments to make about his time at Birmingham where he became a big favourite with supporters.
He told the Sunday Mercury: "When I saw Joe, he told me about the club, the goalkeeping coach (Dave Watson), the manager, things like that, what the lads are like.
"He only had positive things to say about Birmingham, how much of a good time he used to have. You saw he didn't really want to go back to Manchester City.
"He wanted to stay here for another season, which was understandable because he had a good year and you just want to be playing first team football.
"Now I am hoping my move to Birmingham has the same positive effect on my career."