The centre is one of five Glasgow academy talents named in the matchday 23 by Head Coach Kenny Murray, as the men in blue travel to London to take on their hosts at the Twickenham Stoop.
Sitrling Wolves duo Callum Norrie and Harris McLeod are both named amongst the starting pack, lining up at tight-head and second-row respectively for Murray's men.
Ben Afshar lines up at scrum-half, the Ayrshire Bulls man given the nod ahead of fellow Glasgow academy star Finlay Burgess, who is included amongst the replacements.
Co-captain Munn completes the Warriors contingent in the matchday 23, starting at outside centre a year on from making his Scotland U20 debut against the same opposition.
Rugby in Glasgow and the west of Scotland is also well represented amongst the matchday 23; Ayrshire Bulls fly-half Richie Simpson joins GHA duo Jonny Morris and Amena Caqusau, as well as Glasgow Hawks standouts Kerr Yule, Moby Ogunlaja and Ruaraidh Hart in the matchday squad.
Scotland U20
15 Dan King** (Heriot's Rugby)
14 William Robinson (Caldy RFC)
13 Duncan Munn* (Boroughmuir Bears/Glasgow Warriors)
12 Kerr Yule** (Glasgow Hawks)
11 Amena Caqusau** (GHA RFC)
10 Richie Simpson (Ayrshire Bulls)
9 Ben Afshar* (Ayrshire Bulls/Glasgow Warriors)
1 Max Surry (Cardiff Met University)
2 Corey Tait** (Boroughmuir Bears)
3 Callum Norrie* (Stirling Wolves/Glasgow Warriors)
4 Jake Parkinson (Ealing Trailfinders/Brunel University)
5 Harris McLeod* (Stirling Wolves/Glasgow Warriors)
6 Liam McConnell* (Boroughmuir Bears/Edinburgh Rugby)
7 Rudi Brown* (Southern Knights/Edinburgh Rugby)
8 Jonny Morris* (GHA RFC)
Substitutes is
16 Jerry Blyth-Lafferty** (Boroughmuir Bears)
17 Craig Davidson (Watsonian RFC)
18 Moby Ogunlaja (Glasgow Hawks)
19 Eddie Erskine (Bath University)
20 Ruaraidh Hart** (Glasgow Hawks)
21 Sam Derrick** (Southern Knights)
22 Finlay Burgess* (Stirling Wolves/Glasgow Warriors)
23 Geordie Gwynn (Ealing Trailfinders/Brunel University)
*FOSROC Scottish Rugby Contracted Academy Player
**FOSROC Scottish Rugby Regional Academy Player