Foster has been sidelined by hernia problems since early November but is back in training after two operations and could reclaim his first-team place from Boaz Myhill, who has deputised for the last seven games, this weekend.
"I played in the Southampton game (on November 5), when we won 2-0, and I couldn't kick with my left foot because every time I kicked the ball there was a nerve getting pressed underneath my hernia, which was quite painful," Foster told www.wba.co.uk.
"I had to kick with my right foot because I had no pain on my right side.
"I got away with it because I could do all of the goalkeeping stuff fine, but as soon as I tried to kick a ball it was jumping out of your skin time!
"I was never coming off, because it was only kicking with my left foot that I couldn't do.
"I've had groin issues recently but they think all of that was connected to the hernia, so hopefully this will solve all of that. It was really a double-hernia operation.
"I started training properly yesterday so we will see how training goes this week and take it from there. I trained fine yesterday. I felt absolutely fine."
Defender Steven Reid is set to miss out for a second successive match due to the bruised shin he sustained in the 2-0 defeat at Arsenal on December 8.