Real Madrid's Gareth Bale and Liverpool's Ben Woodburn were among the names missing as Ryan Giggs named his Wales squad for the friendly against Mexico in Pasadena, California, on May 28.
The two forwards will both be participating in the Champions League final in Kiev, Ukraine, two days earlier.
They both featured in Wales' victory over hosts China and a defeat against Uruguay in friendlies as part of the China Cup in March -- Giggs' first two games in charge of the side.
Stoke City midfielder Joe Allen is also absent with a foot injury, but Everton's Ashley Williams and Arsenal's Aaron Ramsey were included in a squad featuring eight uncapped players.
Wales' 32-man squad:
Goalkeepers: Adam Davies (Barnsley), Wayne Hennessey (Crystal Palace), Chris Maxwell (Preston North End), Luke Pilling (Tottenham Hotspur)
Defenders: Cameron Coxe (Cardiff City)Ben Davies (Tottenham Hotspur), Chris Gunter (Reading), Declan John (Rangers), Tom Lockyer (Bristol Rovers), Adam Matthews (Sunderland), Christopher Mepham (Brentford), Regan Poole (Manchester United), Ashley Richards (Cardiff City), Connor Roberts (Swansea City), Joe Rodon (Swansea City), Ashley Williams (Everton)
Midfielders: Lee Evans (Sheffield United), Ryan Hedges (Barnsley), Andy King (Leicester City), Joe Ledley (Derby County), Dan James (Swansea City), Aaron Ramsey (Arsenal), Matthew Smith (Manchester City), George Thomas (Leicester City), George Williams (St. Johnstone), Marley Watkins (Norwich City)
Forwards: Tom Bradshaw (Barnsley), David Brooks (Sheffield United), Hal Robson-Kanu (West Bromwich Albion), Tom Lawrence (Derby County), Sam Vokes (Burnley), Harry Wilson (Liverpool)