Alex McLeish has tipped Scott McTominay to have a 'massive future' with Scotland after selecting him in his first squad since taking over.
The Lancaster-born Manchester United midfielder is one of six players receiving first call-ups after he pledged his international future to the native country of his Glaswegian father despite an approach from England.
Jose Mourinho has handed the 21-year-old starts in crucial games against Sevilla, Chelsea and Liverpool in recent weeks and McTominay has helped United secure positive results each time.
SCOTLAND SQUAD TO FACE COSTA RICA AND HUNGARY
Goalkeepers: Jordan Archer (Millwall), Alan McGregor (Hull City), Jon McLaughlin (Heart of Midlothian)
Defenders: Barry Douglas (Wolverhampton Wanderers), Grant Hanley (Norwich City), Russell Martin (Rangers), Scott McKenna (Aberdeen), Charlie Mulgrew (Blackburn Rovers), Callum Paterson (Cardiff City), Andy Robertson (Liverpool), Kieran Tierney (Celtic)
Midfielders: Stuart Armstrong (Celtic), Tom Cairney (Fulham), James Forrest (Celtic), Ryan Fraser (Aberdeen), Kevin McDonald (Fulham), Dylan McGeouch (Hibernian), John McGinn (Hibernian).