Scotland have named seven uncapped players in their squad for the upcoming friendlies against Peru and Mexico.
"I'm really excited to work with the players included. They have all been guys who have been in really good form for their clubs," national team manager Alex McLeish told the Scottish FA's official website.
"I've known Lewis since he was a kid and he's been very consistent. I've rarely seen a full-back play at such a level throughout a season. So many legends of the game have also echoed my sentiments.
"John Souttar is a good young prospect and been playing under Peter Grant at the Under-21s, progressing very well.
"I love to see young players getting a chance and Lewis Morgan is certainly someone who has emerged."
The Scotland squad in full is as follows
Jordan Archer (Millwall)
Allan McGregor (Hull City)
Jon McLaughlin (Hearts)
Barry Douglas (Wolverhampton Wanderers)
Jack Hendry (Celtic)
Scott McKenna (Aberdeen)
Charlie Mulgrew (Blackburn Rovers)
Callum Paterson (Cardiff City)
John Souttar (Hearts)
Lewis Stevenson (Hibernian)
Stuart Armstrong (Celtic)
Ryan Fraser (Bournemouth)
Dylan McGeouch (Hibernian)
John McGinn (Hibernian)
Kenny McLean (Aberdeen)
Scott McTominay (Manchester United)
Jamie Murphy (Rangers)
Matt Ritchie (Newcastle United)
Graeme Shinnie (Aberdeen)
Ryan Christie (Aberdeen)
Oliver McBurnie (Barnsley)
Lewis Morgan (Celtic)
Matt Phillips (West Bromwich Albion)
Johnny Russell (Sporting Kansas City)