Manchester United striker Tom Lawrence and Fulham winger George Williams have been left out of the Wales Under-21 squad.
Their absence could mean they will be in the senior squad for Wales' Euro 2016 qualifier against Andorra on 9 September.
Barnsley goalkeeper Christian Dibble, son of former Welsh international Andy, could make his debut for the Under-21s.
They face Finland and Lithuania away on 5 and 9 September.
Defender Jordan Williams, midfielders Josh Sheehan and Theo Wharton and forward Bradley Reid are among the other potential new caps.
Wales are fourth in their Euro 2015 Under-21 qualifying group, with 10 points from eight games, 12 points behind leaders England.
|Wales Under-21 squad|
|Daniel Alfei||Swansea City|
|Morgan Fox||Charlton Athletic|
|Elliott Hewitt||Ipswich Town|
|Declan John||Cardiff City|
|George Ray||Crewe Alexandra|
|Joe Walsh||Crawley Town|
|Gwion Edwards||Crawley Town|
|Lee Evans||Wolverhampton Wanderers|
|Tom O'Sullivan||Cardiff City|
|Josh Sheehan||Swansea City|
|Theo Wharton||Cardiff City|
|Wes Burns||Bristol City|
|Ellis Harrison||Bristol Rovers|
|Bradley Reid||Wolverhampton Wanderers|