Lawson is joined in the match day squad by uncapped cousin Jim Thompson, who takes his place among the replacements as Andy Robinson looks to build on his side's 23-20 defeat of Ireland in the final game of this year's Six Nations.
And Lawson, grandson of the late Bill McLaren, has backed himself to revel in the starting role.
"I value every cap as an honour and privilege but there is something a bit different about starting," said Lawson.
"It can almost be easier starting the game because you know exactly how to prepare for it, you can prepare in the warm-up for starting the game whereas being on the bench you are wondering if you will get on.
"Everyone wants to start every game whether it is club or country. That is the position we are in, we are very fortunate with the quality we have at scrum half.
"Mike and Chris have had the lions' share of that over a number of years now so I am delighted to get my opportunity."
Scotland have been drawn in the same pool as Argentina for next year's World Cup in New Zealand and after being recalled to the side fly-half Felipe Contepomi is desperate to lay down a marker.
"I'm very happy to be back after not playing here for some time," said Contepomi.
"We've got to consolidate for the World Cup and take advantage of these moments because we don't have many games."
Argentina: Martin Rodriguez, Lucas Borges, Gonzalo Tiesi, Santiago Fernandez, Horacio Agulla, Felipe Contepomi, Alfredo Lalanne; Rodrigo Roncero, Mario Ledesma, Martin Scelzo, Manuel Carizza, Patricio Albacete, Genaro Fessia, Juan Manuel Leguizamon, Juan Martin Fernandez Lobbe.
Replacements: Agustin Creevy, Marcos Ayerza, Mariano Galarza, Alejandro Campos, Agustin Figuerola, Ignacio Mieres, Lucas Gonzalez Amorosino.
Scotland: Hugo Southwell, Max Evans, Nick De Luca, Graeme Morrison, Sean Lamont, Dan Parks, Rory Lawson; Allan Jacobsen, Ross Ford, Moray Low, Jim Hamilton, Alastair Kellock, Kelly Brown, John Barclay, Johnnie Beattie.
Replacements: Scott Lawson, Geoff Cross, Scott MacLeod, Alasdair Strokosch, Mike Blair, Phil Godman, Jim Thompson.