Partick Thistle duo Stephen O'Donnell and Stuart Bannigan have been rewarded for their good recent form while Kilmarnock forward Rory McKenzie has a chance to impress.
There is also a call for Celtic goalkeeper Robbie Thomson as first-choice Jordan Archer, who is on loan at Wycombe from Tottenham, has been omitted as Wanderers have a league match on Monday.
Stuart Armstrong, Rhys McCabe and Tony Watt are all recalled after sitting out the 3-2 friendly defeat to Portugal in November through injury.
The draw for the UEFA European U21 Championship is due to take place on Thursday and Scotland could play their first qualifier as early as March.
Stark said: "This might be our last opportunity before a potential qualifier in March and we need to make sure we are ready.
"Greece will present us with a good test.
"Stephen O'Donnell and Stuart Bannigan have been playing really well this season and Robbie Thomson has been involved in international youth squads before.
"I've also included Rory McKenzie who has been with us at U19 level and acquitted himself quite well."
Scotland U21 squad: Kettings (Blackpool), Thomson (Celtic), Duffie (Falkirk), McHattie (Hearts), O'Donnell (Partick), Robertson (Aberdeen), Toshney (Celtic), Wallace (Huddersfield), Armstrong (Dundee United), Bannigan (Partick Thistle), Fyvie (Wigan), Holt (Hearts), McCabe (Sheffield Wednesday), Scougall (Livingston), McGeouch (Celtic), McKenzie (Kilmarnock), Smith (Heart), Watt (Celtic).