Craig Levein believes new boy Matt Phillips and James Forrest represent the future for Scotland.
Blackpool striker Phillips, 20, has been handed his first call-up by Levein for next week's friendly in Slovenia, while Celtic winger Forrest will miss the U21 clash with Holland as Levein wants to include him in his preparations for the World Cup qualifiers which begin in September.
The Scotland boss said: "James could have been playing for the under-21s for Billy against Holland but I feel he fits the bill of an international football player and I consider him and Matt Phillips two who are very much in mind for playing international games in the future."
Levein added: "Both are very quick, very direct and capable of scoring goals and I am very excited about the prospect of those two linking up and they certainly have the best years ahead of them.
"My plan is that James will be involved from the start of this game, I wouldn't have taken him if I wasn't going to play him.
"It is a really important game. I think every has to realise that this is the start of our World Cup campaign. We only have a game against Slovenia, a game in the United States in the summer and a game in August.
"We have three matches to prepare for the competitive games and so it is really important that we get people bedded in. Anybody who gets the opportunity to play between now and September has the chance to force themselves into the team."
Phillips was born in Aylesbury and has represented England at under-19 and under-20 level but has opted to play for Scotland, for whom he qualifies through his grandparents.
Levein, who also called up Celtic defender Charlie Mulgrew, is "excited" about the addition of Phillips to his squad, subject to FIFA clearance.
He said: "Great things are expected of him. I'm hoping that FIFA can push along the process and we can get him available for the game."