The West Bromwich Albion goalkeeper decided to call time on his international career last season after failing to make a number of Fabio Capello's squads.
However, the 28-year-old could be prepared to reverse his decision should the manager require his services.
"At the moment, I play my club football; I go home and have time with my family. That's absolutely brilliant. That's how I operate best as a footballer," said Foster.
"But if something does happen to Joe [Hart], and the manager gives me a call and says 'we're desperate for you to come back in' then I can consider it. I can always consider it.
"Even players that are fully retired from international football can consider coming back. That's always the case for them as well.
"You've seen it with Jamie Carragher and Paul Scholes, people like that. Even if you're fully retired, you never fully close the door."
Foster joined West Brom this summer on a loan deal from Birmingham City.