Foster withdraws from England squad
The West Brom shot-stopper was set to be involved in Wednesday's friendly with Norway at Wembley but will now be unavailable for that clash and England's opening UEFA Euro 2016 qualifier with Switzerland in Basle next Monday.
Foster, 31, picked up the blow in training on Monday and has now returned to West Brom as a precautionary measure.
West Brom's director of football administration Richard Garlick told the club's official website: "We will spend the next few days letting it settle down and then assess it again – but at this stage we are optimistic it is not a serious problem.
"It made sense for Ben to take no chances."
Foster's withdrawal leaves Manchester City's Joe Hart and Southampton's Fraser Forster as the only two goalkeepers in Roy Hodgson's squad.