And the England man believes Edwin van der Sar could play for another four years!
Foster said: "I love it at Birmingham - it's a great team. I feel needed and relied on and I thrive on that.
"The last few years at United were not so great for me because I was in and out of the team.
"People say Edwin won't go on forever - they obviously don't know him!
"He's so fit he could go on for another three or four years."