Wayne Hennessey has been ruled out of Wales' Euro 2016 opener against Slovakia in Bordeaux.
The 57-times capped Crystal Palace goalkeeper is understood to have a suffered a back spasm before Wales' first game at a major tournament for 58 years.
Hennessey's absence is a big blow for Wales as he played in all 10 matches during the qualifying campaign, conceding only four goals.
Liverpool's Danny Ward will replace Hennessey as he starts a Wales game for the first time.
Ward's only two previous appearances for Wales came as a substitute.
The 22-year-old played in the 1-1 draw against Northern Ireland in March and the 3-0 defeat to Sweden in Stockholm last weekend.