Hart benefited from a season-long loan at Blues and has been Fabio Capello's first choice keeper for the opening three internationals of the current campaign. But Foster has gone down the same route in moving from Manchester United to St Andrew's in a £6million summer move.
He has started the season in fine form for Blues and Clemence believes he can push Hart all the way in the battle for the England jersey.
Clemence told Press Association Sport: "Ben is injury free, which he hasn't been for a number of seasons, and like Joe Hart last season, he is playing regular football.
"If I looked at Joe in the first two months of last season, I could see decision-making errors because he hadn't been playing regularly. During the last two months of last season he was as good as anyone in the division, and playing regularly gives you those opportunities.
"But I am sure that Ben can push Joe. Joe is young, he wants to learn, is enthusiastic, has got great technical ability, is a good distributor of the ball which you need as a keeper these days.
"Ben is now playing regularly and is capable of pushing him and that's what you want as a manager."