Goalkeeper Foster yesterday completed his £6m move from Manchester United, signing a three-year contract at St Andrews.
McLeish moved quickly to replace Hart, who was recalled by Manchester City after enjoying an outstanding campaign in the Midlands.
Hart’s form could even see him take the England No1 jersey at this summer’s World Cup, and McLeish expects Foster to make a similar impact.
“It looks as if we’ve got another great acquisition with Ben Foster,” said McLeish.
“Goalkeeper is a massive position and we’ve now signed another young hungry goalkeeper who wants to prove himself and live up to his potential. We believe he is of the same kind of standard as Joe Hart.”