Bain will be hoping to win his first cap in the upcoming games, having only once been called up to the senior national side.
Alex McLeish's men face Peru on May 30, before taking on Mexico four days later as part of their American tour.
Updated Scotland squad:
Goalkeepers: Jordan Archer (Millwall), Scott Bain (Celtic), Jon McLaughlin (Hearts)
Defenders: Jack Hendry (Celtic), Scott McKenna (Aberdeen), Charlie Mulgrew (Blackburn Rovers), Stephen O'Donnell (Kilmarnock), Callum Paterson (Cardiff City), John Souttar (Hearts), Lewis Stevenson (Hibernian).
Midfielders: Stuart Armstrong (Celtic), Chris Cadden (Motherwell), Dylan McGeouch (Hibernian), John McGinn (Hibernian), Kenny McLean (Aberdeen), Scott McTominay (Manchester United), Jamie Murphy (Rangers), Graeme Shinnie (Aberdeen), Ryan Christie (Celtic).
Forwards: Ollie McBurnie (Swansea City, on loan at Barnsley), Lewis Morgan (Celtic), Matt Phillips (West Bromwich Albion), Johnny Russell (Sporting Kansas City)