Fly-half Dan Parks has warned Scotland will need to put together their best performance of the World Cup if they are to beat "never-say-die" quarter-final opponents Argentina.
Parks is aware his side only played in fits and starts during the pool stages and he believes that will not be enough to down the Pumas.
Scotland have not beaten Argentina since 1990 and two years ago they lost 23-19 in a nail-biter at Murrayfield.
Parks said: "That was an interesting game. I think we were always in control but in the end we lost and that's the type of team they are - they never say die.
"They were very tough to play against and we are all well and truly aware of that.
"Their game is about possession and territory. Once they get in that position on the field, they stay there until they get some sort of points."
At stake for Scotland on Sunday is a first appearance in the World Cup semi-finals since 1991, when they were beaten by England.
Parks continued: "We haven't really shown too much at this stage. I think there have been stages where we have played enterprising play, but at the weekend against Italy we didn't get much of a chance with the weather.
"As players, we would like to have played a bit more rugby. With the Portugal game, we showed glimpses of good play. Romania was similar, wet greasy conditions but in the end we slugged it out and scored six tries.
"And then New Zealand. I can't remember having the ball too many times in a good attacking position, it was all defensive in that second half."
Argentina, in contrast, have produced two huge performances to beat World Cup hosts France and Ireland.
But they will be wary of the need for strict discipline given first-choice kicker Chris Paterson and Parks are yet to miss a shot at goal all tournament.
Kicking coach Duncan Hodge said: "They have both kicked brilliantly so far.
"These two guys know exactly what they are doing and it's not about me changing things.
"They know their games well enough at this stage of their careers. It's more me helping them if they want anything."