Cardiff City defender Oliver Denham has received a first Wales call-up - but uncapped Nathan Broadhead has been forced to withdraw from the squad for June's World Cup play-off final and four Nations League matches.
Denham, 20, has played just five Championship and two cup games this season for Cardiff.
Manager Robert Page has also recalled Ipswich winger Wes Burns to his squad.
Forward Broadhead's withdrawal is because of injury.
The 24-year-old scored 13 goals in 27 appearances for Sunderland on loan from Everton this season and was included for the first time when Page last week named an extended 27-man squad seemingly designed to help manage a congested summer fixture list.
His side face either Scotland or Ukraine in Cardiff on Sunday, 5 June, as Wales aim to qualify for a first World Cup since 1958.
Four days before that huge encounter, Wales visit Poland in the Nations League. They then host the Netherlands and Belgium on 8 and 11 June, before travelling to the Netherlands for their final game of this window on 14 June.
Burns has previously featured in Wales' squads under former manager Chris Coleman but is also uncapped.