Scotland coach Frank Hadden has named three new caps in the side to face Argentina on Saturday while Chris Paterson will equal Scott Murray's record cap total.
Edinburgh pair Ben Cairns and Matt Mustchin, the New Zealand-born lock who only qualified for Scotland through residency rights last week, will join Glasgow winger Thom Evans in making their Scotland debuts.
At the other end of the spectrum, Paterson will make his 87th full international appearance when Scotland play the first of two Tests against Argentina in Rosario.
Hadden, who has also recalled number eight Johnnie Beattie, said: "I've been tracking Ben Cairns since he was 17 as he looked like a future outside centre.
"He is very mature both on and off the field and has the ability to play his role so it brings out the best of those around about him.
"I spoke to Thom before the World Cup and told him that his whole season should be geared to getting on the plane to Argentina. He thoroughly deserves this opportunity as he's a very exciting talent.
"Matt is abrasive and combative - the sort of qualities that will be ideally suited to the forward battle with the Pumas this weekend."
"We must win the series to go up the rankings. We have no choice.
"We cannot go into the next World cup with a seeding of 10th.
"We have a very difficult job, as Argentina had in the past with other better placed teams.
"It is very difficult to progress if you don't win these matches. You need to be on top to have a good seeding in the World Cup."
He explained: "The key for playing for Scotland it is to play consistently well.
"It is not about having a good game here and there; it is not about suddenly appearing on the scene and looking like you could play at international level. It is about playing constantly well at a club level."
Hadden, speaking at a press conference at the Panamericano Hotel in Buenos Aires, continued: "That is also the reason that I have named Ben, Thom and Matt. They have performed constantly well for the last year and have shown a lot of determination and courage."
Hadden expects 23-year-old Evans to be one of the most outstanding players not only in the match but also in the future with Scotland.
He continued: "Thom, we think, should be a very good player in two years time - but he is the best this weekend, so he is in.
"He is a very exciting talent and I think that everybody here will be very impressed with him."
Evans is confident and hopes the Argentinian crowd at Gigante de Arroyito stadium make as much noise as possible to release his fearless personality.
He explained: "I was very nervous when I was told the team selection - but as training's gone on the last couple of days I was really excited to have this chance.
"Playing against Argentina in Argentina it is a great experience and challenge. We both are very good sides, very tough and physical and passionate.
"I heard that the Argentinian fans are very passionate too and that is what I would expect.
"I react well under pressure and I will try to use that to my own advantage. I hope that could bring the best of me."
Cairns - included in the squad's preparation for the 2007 RBS 6 Nations Championship but then ruled out of the competition - is another jewel that Hadden is waiting to see shine.
Hadden said: "I have been tracking Ben since he was 17 as he looked like a future outside centre.
"He is very mature both on and off the field and has the ability to play his role so it brings out the best in those around about him."
Cairns, in Argentina for the second time after competing there in the 2006 Under-21 World Cup, will try to win a regular spot in the team.
He explained: "This is huge for me. When I got the news I was delighted and honoured, with it being my first time to dress in the national jersey.
"It will be a great experience for me and I hope I can prove that I am the right man.
"I want this match to be the first one of many - but I know it will not be easy from now on."
Lock Mustchin said: "It is an exciting feeling. I have been looking forward to this moment and I hope to play as well as I can on Saturday, not only for me but also for the team."
The 31-year-old Edinburgh man added: "This is my first chance to show what I can do in the national side and I want to make the most of it to win a place in the next World Cup."
After losing their Under-20s Six Nations crown to England Under-20s in a thrilling final round, France Under-20s lock Tristan Labouteley insists his side will be out for revenge at this year's Junior World Championship.