The remaining uncapped players are goalkeepers Jordan Archer [Millwall], Jon McLaughlin [Hearts] and midfielders Dylan McGeouch [Hibernian] and Graeme Shinnie [Aberdeen].
McLeish told 'Sky Sports': ''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.''
''I've known Lewis [Stevenson] 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 U21s, progressing very well. He's still got a lot to learn but he's had a great season under Christophe Berra who would have kept him right.''
''I love to see young players getting a chance and Lewis Morgan is certainly someone who has emerged. I've had a lot of feedback from people who have worked with him and he's really dynamic.''
McLeish concluded: ''We need to start encouraging that level of talent.''
Check out the full Scotland squad below:
Goalkeepers: Jordan Archer, Allan McGregor, Jon McLaughlin.
Defenders: Barry Douglas, Jack Hendry, Scott McKenna, Charlie Mulgrew, Callum Paterson, John Souttar, Lewis Stevenson.
Midfielders: Stuart Armstrong, Ryan Fraser, Dylan McGeouch, John McGinn, Kenny McLean, Scott McTominay, Jamie Murphy, Matt Ritchie, Graeme Shinnie.
Forwards: Ryan Christie, Oliver McBurnie, Lewis Morgan, Matt Phillips, Johnny Russell.