Ben Davies will miss Wales' World Cup qualifier against Serbia on Saturday.
The Tottenham defender suffered an ankle injury during the 1-0 Champions League defeat to Bayer Leverkusen last week.
Davies missed the 1-1 Premier League draw at Arsenal on Sunday and his absence is a big blow to Wales.
The 23-year-old was one of Wales' best performers at Euro 2016 last summer as Chris Coleman's side reached the semifinals in France.
Squad Update: @Ben_Davies33 has been withdrawn from the squad through injury and is replaced by @Adam2Matthews #WALSRB #TogetherStronger pic.twitter.com/o0UCytI2Hp
- Wales (@FAWales) November 7, 2016
Sunderland full-back Adam Matthews, who is on loan at Bristol City, has been called into the squad to replace Davies.
Matthews, who has won 13 caps for Wales, has been out of favour in recent times and missed out on Euro 2016 selection.
Wales are unbeaten in World Cup qualifying but trail Group D leaders Serbia by two points after slipping up in a 1-1 home draw against Georgia last month.