Killie trio Eamonn Brophy, Stuart Findlay and Greg Taylor join Rugby Park team-mate Stephen O'Donnell in the squad while Aberdeen defender Mikey Devlin and Livingston goalkeeper Liam Kelly make up the new caps.
Brophy will be competing for a starting berth up front with Reading striker Marc McNulty, who performed well for Hibs during a loan spell in the second half of last season, Sporting Kansas City forward Johnny Russell and West Brom's Oliver Burke, who operated as a number nine for Celtic while on loan at Parkhead.
Findlay and Devlin have been called up to previous squads but are yet to play for their country. Sheffield United midfielder John Fleck misses out due to wedding commitments while Clarke confirmed that Aberdeen midfielder Lewis Ferguson and Motherwell's David Turnbull were very much in his thoughts.
Scotland have a number of players missing through injury or personal reasons, including Celtic trio Ryan Christie, Kieran Tierney and Leigh Griffiths while Robert Snodgrass hasn't played for West Ham since April. Despite scoring just twice on loan at Sunderland and only making the bench for the weekend's play-off loss to Charlton, Lewis Morgan is named in the squad.
However, there is no place in the midfield ranks for Rangers' Ryan Jack, who has been a consistent performer in midfield for the Light Blues. Also omitted are Liam Cooper of Leeds, Sheffield Wednesday's Steven Fletcher and recently released Millwall goalkeeper Jordan Archer.Hamburg defender David Bates, who started Alex McLeish's last two matches in charge, misses out along with Swansea forward Oli McBurnie.
There are recalls, however, for Fulham's Tom Cairney and Hull goalkeeper David Marshall.
McLeish left after the Scots slumped to a 3-0 defeat in Kazakhstan and followed it up with an uninspiring win over San Marino.
Scotland host Cyprus on June 8 before travelling to Belgium to face the Red Devils three days later.
Goalkeepers: Scott Bain (Celtic), Liam Kelly (Livingston), David Marshall (Hull City), Jon McLaughlin (Sunderland)
Defenders: Mikey Devlin (Aberdeen), Stuart Findlay (Kilmarnock), Scott McKenna (Aberdeen), Charlie Mulgrew (Blackburn Rovers), Stephen O'Donnell (Kilmarnock), Liam Palmer (Sheffield Wednesday), Andy Robertson (Liverpool), John Souttar (Hearts), Greg Taylor (Kilmarnock)
Midfielders: Stuart Armstrong (Southampton), Tom Cairney (Fulham), John McGinn (Aston Villa), Callum McGregor (Celtic), Kenny McLean (Norwich City), Scott McTominay (Manchester United), Graeme Shinnie (Aberdeen)
Forwards: Eamonn Brophy (Kilmarnock), Oliver Burke (Celtic, on loan from West Brom), James Forrest (Celtic), Ryan Fraser (Bournemouth), Marc McNulty (Hibs, on loan from Reading), Lewis Morgan (Sunderland, on loan from Celtic), Johnny Russell (Sporting Kansas City).