Tom Marshall will make his debut for Scotland Under-20s, with the Newcastle Falcons forward starting at Number 8 for the age-grade side in their World Rugby Under-20 Championship opener against South Africa in Rosario on June 4.
Watsonians' Connor Boyle captains a team containing ten Fosroc Scottish Rugby Academy players in the starting line-up.
Marshall is one of just three changes to the side that lined up against England in the final match of the 2019 Under-20 Six Nations competition.
Stirling County's Grant Hughes starts at inside centre while Marshall Sykes of Ayr gets the nod at blindside flanker, despite missing the Six Nations through injury.
Sykes and Marshall form a new-look back-row with captain Boyle making his sixth consecutive start for Scotland Under-20s at openside
London Scottish fullback Matt Davidson makes his tournament bow, and is joined by Heriot's duo Jack Blain and Rory McMichael in the back-three.
Sale Sharks hooker Ewan Ashman packs down in the front-row alongside highly-rated props Murphy Walker of Stirling County and Ayr's Euan McLaren.
Racing 92 lock Ewan Johnson is joined in the second-row by Walker's Stirling colleague Cameron Henderson.
Head Coach Carl Hogg said: “We open this year’s World Rugby U20 Championship against a tough and physical Springboks outfit, but we have selected an exciting side that has the ability to threaten any defence.
“As a squad, we’ve enjoyed a hard training week in Washington, as well as a pre-tournament game against Old Glory DC that will stand us in good stead leading into this week’s physical contest with South Africa.
“It’s really important that we get off to a good start, so it’s imperative that we play with real tempo in our game, but also make smart decisions on where we play the game.
“There is no doubt that South Africa will bring a physical approach with a strong set piece. We need to ensure that we contest at every opportunity.
“We know how tough a test we face, but we can’t wait for the challenge that awaits us in Rosario."
Scotland Under-20 team to face South Africa Under-20s at the Racecourse Stadium in Rosario, kick-off 2.30pm BST on Tuesday June 4
15. Matt Davidson (London Scottish), 14. Rory McMichael (Heriot’s), 13. Cameron Anderson (Wasps), 12. Grant Hughes (Stirling County), 11. Jack Blain (Heriot’s), 10. Ross Thompson (Glasgow Hawks), 9. Roan Frostwick (Currie Chieftains), 1. Murphy Walker (Stirling County), 2. Ewan Ashman (Sale Sharks), 3. Euan McLaren (Ayr), 4. Ewan Johnson (Racing 92), 5. Cameron Henderson (Stirling County), 6. Marshall Sykes (Ayr), 7. Connor Boyle (Watsonians), 8. Tom Marshall (Newcastle Falcons).
16. Rory Jackson (Edinburgh Academy), 17. Andrew Nimmo (Glasgow Hawks), 18. Will Hurd (Cardiff Metropolitan University), 19. Mak Wilson (Melrose), 20. Ross Bundy (Stirling County), 21. Jack Hill (Durham University), 22. Kwagga van Niekerk (Lions), 23. Murray Scott (Watsonians), 24. Teddy Leatherbarrow (Sale Sharks), 25. Nathan Chamberlain (Bristol Bears), 26. Robbie McCallum (CR Cisneros), 27. Ollie Smith (Ayr), 28. Lomond MacPherson (Watsonians).