The pair have received their first senior England call-ups due to injuries to their compatriots. Drinkwater's injury is yet to be dislosed while Forster is suffering with a abdominal problem.
While the decision to replace Drinkwater with a defender may come as a surprise, left-back Danny Rose is understood to be struggling with a hamstring problem, meaning the Hammers defender will provide cover for the Spurs man.
Meanwhile, goalkeeper Fraser Forster has an abdominal problem and Southgate has given a first senior call-up to 22-year-old Pickford who has been one major positive in an otherwise dismal season for Sunderland. Pickford produced a man-of-the-match display against Bournemouth on Saturday as Sunderland won their first game of the season.
England and Scotland go head to head on Friday and the result of the match may decide each side's managers' futures. A win for Southgate is likely to secure the job on a full-time basis whereas a loss for the Scots may be the final straw for Gordon Strachan as manager of Scotland.