For both Argentina and Scotland, familiarity breeds respect.
The teams will meet today for the sixth time in four years in Pool B, this time in a Rugby World Cup match which likely will decide who proceeds to the tournament's knockout stages and who makes an early exit.
Scotland have reached the quarter-finals at every World Cup since the tournament was founded 24 years ago, while Argentina were the surprise package of the last World Cup as they reached the semi-finals before losing to eventual winners South Africa.
Argentina's Pumas beat Scotland in Edinburgh in 2009 and Scotland won both Tests played in Argentina last year, making today's match one of the hardest to pick in pool play.
Even Andy Robinson, the Scotland coach, when asked to name a favourite, said: "I'd say it's 50-50. Both sides are very good sides that have played against each other a lot, so we know each other pretty well."
Few teams in world rugby place more emphasis than Argentina on the scrum. It is the nucleus of their game, a physical contest which suits the macho ethos which permeates the Argentine game.
In recent meetings, Argentina and Scotland have fought for control through the scrum and Robinson said the scrum confrontation will likely be critical again today. But he is not prepared to accept that the match might be one-dimensional.
"We really want to play ball in hand. That's something that's the key for us," Robinson said. "We want to get out and go at Argentina.
"They are strong around the breakdowns and therefore our ability to move their forward pack around will be important for us."
Scotland's scrum has been disrupted by the unavailability for this match of tighthead-prop Euan Murray, who does not play on Sundays because of his religious beliefs.
Murray's place has been taken by Rory Cross but his absence has also forced Robinson to name giant lock Jim Hamilton in his starting XV.
Hamilton's selection, in turn, has left no place in the Scottish squad for the lock and tournament captain Al Kellock, leaving the captaincy in the hands of Rory Lawson, the scrum-half.
The pre-match build-up could be described as a tale of two captains. While Kellock's non-selection was the key feature of Scotland's selection, the return from injury of the captain Felipe Contepomi was the highlight of Argentina's.
Contepomi has played only 25 minutes at the tournament, leaving the field with a rib injury in his team's opening loss to England. He won a race against time to be fit and returns at inside centre to steer his team.
"It's the most important game because it's the next game," Contepomi said. "It's one that we have to win and that's it.
"At the same time we approach it the same as we approached the last two games in the World Cup, to prepare well, to have a good training week, to try to analyse Scotland and play to our strengths."
In today's other action, Ireland will look to go back to the top of Pool C with a win over the basement side Russia.
The Irish, who caused the biggest upset in the tournament to date when they beat Australia last Saturday, and Rory Best, the hooker, said the team were not going to rest on their laurels.
The victory over Australia "means nothing if we don't push on and improve", he said.
"Each game has its own time slot so the world is watching each game. It's important we don't let ourselves down this Sunday."
In Pool D, Fiji and Samoa meet, with both sides needing to win to keep alive hopes of reaching the quarter-finals