Having watched fly-half Gareth Steenson kick eighteen points in last Saturday's 33-21 defeat of Italy, McDermott has been included London Irish's Kieran Geraghty in midfield, for Tom Gleeson of UCC.
The pack will also operate with a different hooker as Saracens' Stuart Philpott has been given the nod, and Malone number 8 Chris Henry (pictured, above) starts in place of Garryowen's Anthony Kavanagh.
UCD's Stephen Grissing - who scored his first AIB League try in the students' 19-13 defeat of Galwegians last month - has also been introduced as a replacement.
RBS UNDER-21 SIX NATIONS CHAMPIONSHIP: Friday February 11, Falkirk Community Stadium 7.30pm:
IRELAND U21 (v Scotland U21):
(15) Mark Kettyle (Belfast Harlequins)(14) Tommy Bowe (Belfast Harlequins)(13) Andrew Trimble (Ballymena)(12) Kieran Geraghty (London Irish) (11) Paul McKenzie (Belfast Harlequins)(10) Gareth Steenson (Dungannon) (Capt)(9) Cillian Willis (UCD)(1) Michael Diffley (Buccaneers)(2) Stuart Philpott (Saracens)(3) John Andress (Belfast Harlequins)(4) Mark Melbourne (Garryowen)
(16) Joseph Merrigan (Corinthians)(17) Eamonn Bracken (Buccaneers)(18) Ryan Caldwell (Dungannon)(19) Anthony Kavanagh (Garryowen)(20) David O'Leary (UCC)(21) Barry Keeshan (Cork Constitution)(22) Stephen Grissing (UCD)
Coach: Mark McDermottAssistant Coach: Brian WalshManager: David Haslett