Six of the squad return to under-20 action having experienced the IRB Junior World Championships in Japan last season.
"It's a real help to have these experienced players involved. Obviously the 6 Nations is a different environment to the Junior World Championship but any experience within the intense under-20 competitive environment will stand these players in good stead for the campaign and help them lead the other players," said John.
"The 6 Nations is every bit as tough as the IRB Junior World Championships and is a fantastic experience for the players who have grown up with the tournament, and will have likely been inspired to play rugby by the competition itself.
"It's a fantastic environment to prepare Scotland's top young players for the professional game."
John added: "Oliver has fitted in well to the squad to date and looks to be an individual capable of playing a few positions, which offers good flexibility to the group. It's certainly exciting times for the Grove brothers and Scotland.
SCOTLAND UNDER-20 SQUAD FOR THE 2010 6 NATIONS
Craig Owenson (Heriot's)**, Nicky Little (Hawick)*, Nick Fraser (Boroughmuir), George Hunter (Glasgow Hawks), Colin Philips (Stewart's Melville)**, Alun Walker (Currie), Lindsey Gibson (Melrose), Calum Taylor (Glasgow Hawks), Robert Harley (West of Scotland)*, Grant Gilchrist (Stirling County)*, Aaron Hall (Newcastle Falcons), Matthew Reid (Heriot's), David Denton (Edinburgh Accies)*, Michael Maltman (Heriot's)**, Stuart McInally (Watsonians)*, Calum Stidston-Nott (London Scottish), Michael Fedo (Watsonians), Chris Thomson (Loughborough University)
Kris Hamilton (Caithness)**, Alex Black (Leeds Carnegie), Alex Blair (Edinburgh Accies)*, Matthew Scott (Currie)**, Ross Aitken (Howe of Fife)**, Alex Dunbar (Selkirk)*, Jonny Kennedy (Sale Sharks), Michael Tait (Newcastle Falcons), George Watkins (Bristol Rugby), Tom Brown (Edinburgh Accies)*, Oliver Grove (Worcester Warriors), Callum McBurnie (Moseley), Dougie Fife (Currie)**, James Johnstone (Currie)*
* Denotes a member of the Scottish National Contracted Academy
** Denotes a member of the Scottish Rugby National Academy supported by the Scottish Institute of Sport
SCOTLAND UNDER-20 6 NATIONS SCHEDULE
Friday 5 February, Scotland under-20 v France under-20 (Tulloch Caledonian Stadium. kick -off 7.30pm)
Friday 12 February, Wales under-20 v Scotland under-20 (Cardiff Arms Park, kick-off 7.05pm)
Friday 26 February, Italy under-20 v Scotland under-20 (Capoterra, Sardinia, kick-off 5pm tbc local)
Friday 12 March, Scotland under-20 v England (Firhill, kick-off 7pm)
Friday 19 March, Ireland under-20 v Scotland under-20 (Dubarry Park, Athlone, Ireland, kick-off 7.35pm)