Midfielder Jack Collison has pulled out of the Wales squad for the friendly against Netherlands on 4 June.
Collison, 25, recently released by West Ham United, has pulled out because of injury and will not be replaced in the squad.
Champions League winner Gareth Bale has also pulled out of the squad.
The Football Association of Wales confirmed that the Real Madrid forward, 24, has been "troubled with a leg muscle injury for a few weeks".
Bale's goal-scoring performance helped Real Madrid win the Champions League last week against Atletico Madrid.
Fulham's highly rated 18-year-old striker George Williams has been added to Chris Coleman's squad for the friendly at the Amsterdam Arena.
Arsenal's FA Cup winner Aaron Ramsey along with Swansea City defenders Ashley Williams and Ben Davies have been rested.
However, Wales were boosted earlier in the week by the addition of defender Chris Gunter, who had not been included in Coleman's original squad because of injury.
Goalkeepers: Wayne Hennessey (Crystal Palace), Connor Roberts (unattached), Owain Fon Williams (Tranmere Rovers)
Defenders: Chris Gunter (Reading), James Chester (Hull City), Paul Dummett (Newcastle United), Danny Gabbidon (Crystal Palace), Declan John (Cardiff City), Lewin Nyatanga (Barnsley), Ashley Richards (Swansea City), Neil Taylor (Swansea City)
Midfielders: Joe Allen (Liverpool), Emyr Huws (Manchester City), Owain Tudur Jones (Hibernian), Andy King (Leicester City), Tom Lawrence (Manchester United), Joe Ledley (Crystal Palace), David Vaughan (Sunderland), Jonathan Williams (Crystal Palace)
Forwards: Simon Church (Charlton Athletic), Jermaine Easter (Millwall), Hal Robson-Kanu (Reading), George Williams (Fulham).