Preview: Scotland v Argentina
Semifinalists at last year's World Cup in England, the Pumas dropped from sixth to eighth in the world rankings after their 20-24 defeat by Wales in Cardiff last weekend.
They need to retain a top-eight position to avoid the prospect of being drawn to face two nations from the upper two tiers in the pool stages of the 2019 World Cup in Japan.
Argentina only have two more chances to gain ranking points before May's pool draw – against Scotland in Edinburgh on Saturday and in next week's clash with England at Twickenham.
They will be overtaken by Scotland, currently ninth in the standings, if they fail to win at Murrayfield.
"It's an important match for us in every respect," said Ortega Desio. "We are under the pressure of having to win. It is our responsibility to improve on what we did against Wales.”
The Pumas took a long time to get into their attacking stride against Wales, struggling in the scrums and conceding 11 first-half penalties.
Jet-lag, however, could have played a part in their downfall given Argentina travelled from Buenos Aires to play in Tokyo the previous Saturday for their 54-20 thrashing of Japan.
Scotland suffered their own disappointment last Saturday but played an impressive brand of open rugby before conceding a late converted try in a 23-22 loss to Australia
"Scotland were close to beating Australia and they are a team who have improved a lot in recent years," said Ortega Desio.
"They are orderly in defence and they always cause us problems.
"We cannot underestimate them. It would be a serious mistake."
Argentina have not beaten Scotland since a 13-12 World Cup pool win in Wellington in September 2011.
Pumas coach Daniel Hourcade has named an unchanged starting XV for only the second time in his three-year tenure, with former Toulon flyhalf Nicolas Sanchez collecting his 50th cap.
Scotland coach Vern Cotter will want to guide his squad into the top eight before making way for Glasgow's Gregor Townsend in June and leaving for Montpellier.
Cotter boasts a 2-0 record against the Pumas, courtesy of a 21-19 win in Cordoba in June 2014 and a 41-31 victory in his first Murrayfield match as Scotland boss in November of the same year.
The New Zealander has made four changes, with Edinburgh blindside flank Magnus Bradbury poised for a Test debut.
Grant Gilchrist has replaced injured lock Richie Gray, Fraser Brown has come in for hooker Ross Ford and Tommy Seymour has taken over from left wing Tim Visser.
Scotland captain Greig Laidlaw acknowledged the significance of Saturday's match by saying: "It's clearly very important.
"We know about the ranking points, but they will be in the back of our minds."
The scrumhalf added: "If we concentrate on ourselves and play for the full game then we have a better chance of winning, and the ranking points will take care of themselves."
Recent results:
2014: Scotland won 41-31, Edinburgh
2014: Scotland won 21-19, Cordoba
2011: Argentina won 13-12, Wellington (World Cup pool match)
2010: Scotland won 13-9, Mar del Plata
2010: Scotland won 24-16, Tucuman
2009: Argentina won 9-6, Edinburgh
2008: Scotland won 26-14, Buenos Aires
2008: Argentina won 21-15, Rosario
2007: Argentina won 19-13, Paris (World Cup quarterfinal)
2005: Argentina won 23-19, Edinburgh
Prediction: Given the expected conditions, don't expect much expansive rugby. It will be a dour arm-wrestle and very little will separate the teams. Argentina will sneak it by five points or less.
Teams:
Scotland: 15 Stuart Hogg, 14 Sean Maitland, 13 Huw Jones, 12 Alex Dunbar, 11 Tommy Seymour, 10 Finn Russell, 9 Greig Laidlaw (captain), 8 John Barclay, 7 Hamish Watson, 6 Magnus Bradbury, 5 Jonny Gray, 4 Grant Gilchrist, 3 Zander Fagerson, 2 Fraser Brown, 1 Allan Dell.
Replacements: 16 Ross Ford, 17 Alex Allan, 18 Moray Low, 19 Tim Swinson, 20 Ryan Wilson, 21 Ali Price, 22 Pete Horne, 23 Tim Visser.
Argentina: 15 Joaquín Tuculet, 14 Matías Moroni, 13 Matías Orlando, 12 Juan Martín Hernández, 11 Santiago Cordero, 10 Nicolás Sánchez, 9 Martín Landajo, 8 Facundo Isa, 7 Javier Ortega Desio, 6 Pablo Matera, 5 Matías Alemanno, 4 Guido Petti, 3 Ramiro Herrera, 2 Agustin Creevy (captain), 1 Lucas Noguera.
Replacements: 16 Julián Montoya, 17 Santiago García Botta, 18 Enrique Pieretto, 19 Leonardo Senatore, 20 Juan Manuel Leguizamon, 21 Tomás Cubelli, 22 Jerónimo De la Fuente, 23 Juan Pablo Estelles.
Date: Saturday, November 19
Venue: Murrayfield, Edinburgh
Kick-off: 17.00 (17.00 GMT; 14.00 ART)
Expected weather: Wintry conditions – Further showers and frosty. High of just 4°C and low of -1°C
Referee: Ben O'Keeffe (New Zealand)
Assistant referees: Jérôme Garcès (France), Thomas Charabas (France)
TMO: Shaun Davey (England)
Agence France-Presse
