document: Davies suffered an ankle injury during Spurs' 1-0 defeat by Bayer Leverkusen in the Champions League on 2 November.
  He then missed the 1-1 draw at Arsenal in the Premier League on Sunday.
  The 23-year-old had been included in the Wales squad for the qualifier in Cardiff but has now been replaced by Sunderland's Adam Matthews, who is on loan at Bristol City.
  Davies has started in Wales' opening three qualifiers.
  Serbia are top of Group D after three matches on seven points, with Wales third on five points.
summary: Tottenham defender Ben Davies has been ruled out of Wales' World Cup qualifier with Serbia on 12 November.