All that may change tomorrow as Thompson has bounced back from an injury-ravaged season to be named amongst the match day 22 for the first test in Tucuman. While he will be one of the subs, Thompson could make his international debut since the versatile 25-year-old is covering every position on the field outside of fly-half.
His coach Andy Robinson spoke of the class and composure that Thompson brings to every game he plays and also pointed out that, given the Pumas' kicking game, having another full back on the bench was a handy option. But it was just three short years ago that the multi-talented full back was playing Premier One rugby with Heriot's and only dreaming of signing professional forms. Now despite making by his own reckoning "just five or six starts" for Edinburgh this season Thompson is on the brink of joining his cousin Rory Lawson as a full Scotland internationalist.
Like Lawson, Thompson is also a grandson of the late and much-lamented commentator Bill McLaren and they were surely be dancing in the streets of Dollar when the news broke that not only had Thomson won a place on the bench but that Lawson had earned a rare start for Scotland, getting his nose in front of Mike Blair for the first time at full international level. "It offers a bit of hope for everyone I suppose," says Thompson with all modesty about his own achievement. "I was playing Premier One rugby three years ago and I was part of Edinburgh's academy set-up that got transferred over to the national academy. Then I played for the club international team and then I got to the academy where I did a year.
"I am looking forward to it, it's a great honour to be picked in the 22. I just hope I can get on, win my first cap and play as well as I can."
A much-travelled youth, Thompson started his school rugby career with Royal High minis before moving to Stewart's Melville and finishing up latterly at Dollar Academy where he turned out at centre. But Robinson was quick to squash any thought that the new boy might be asked to reprise his schoolboy role. Should either of the starting centres, Graeme Morrison and Nick De Luca, be forced from the field then Max Evans or Sean Lamont would be shuffled in field and so leaving Thompson to guard the widest channel, a challenge that the debutant insists he can handle.
"When I came back from injury I started three or four games on the wing," says Thompson. "I scored two tries on the wing against Ulster and played in a couple of Heineken Cup games to I have some decent experience of playing on the wing at the highest level. I started against Stade Francais on the wing and we won."
It may have been a meteoric rise lately but, as the old saying goes, it's been a while coming. John Barclay was two years below Thompson at school but somehow managed to win his first Scotland cap way back in 2007 although, as the new boy rightly points out, the flanker was always an exceptional talent.
Thompson insists that he is still having to pinch himself to make sure everything is really happening but he does admit that he finally began to believe in his own talents at the very beginning of the season when he was named as part of Robinson's first extended Scotland training squad back in August. His knee injury meant that he couldn't even take part but he recalls the moment with pride all the same.
"I'm watching all the sessions and I wasn't thinking about a cap I was just delighted to be there and to be involved with all these big names.
"Even when it was announced that I was coming here I didn't actually give a thought to being capped or not but I hope I do because it's a great opportunity. It's a pretty big deal so I'm desperate to get on."
He will almost certainly add one more name to Edinburgh's growing international roster.
ARGENTINA M Rodriguez-Gurruchaga; L Borges, G Tiesi, S Fernandez, H Agulla; F Contepomi (captain), A Lalanne; R Roncero, M Ledesma, M Scelzo, M Carizza, P Albacete, G Fessia, JM Leguizamon, JM Fernandez Lobbe. Subs: A Creevy, M Ayerza, M Galarza, A Campos, A Figuerola, I Mieres, L Gonzalez-Amorosino.
SCOTLAND H Southwell; M Evans, N De Luca, G Morrison, S Lamont; D Parks, R Lawson; A Jacobsen, R Ford, M Low, J Hamilton, A Kellock (captain), K Brown, J Beattie, J Barclay. Subs: S Lawson, G Cross, S MacLeod, A Strokosch, M Blair, P Godman, J Thompson.