Wales lock Alun Wyn Jones thinks Argentina's recent experience in the Rugby Championship will make them dangerous opponents next Saturday.
The RBS Six Nations champions open their autumn campaign with a clash against the Pumas as they attempt to try and secure a top-four world ranking before December's 2015 World Cup draw.
While Wales have not played since June, Argentina will arrive in Cardiff on the back of home and away meetings with New Zealand, Australia and South Africa.
"Argentina are fresh from a baptism of fire in the Rugby Championship," Jones said.
"They will be battle-hardened and coming to Wales looking for victory, so we will have to be ready for them.
"We will definitely need to be on our guard. When you come up against these teams you have to front-up and show where you are at as a player.
"Argentina are only going to benefit from being in the Rugby Championship and playing against the best sides in the world.
"They've had a bit of a dent in their pack of late with the retirement of some key forwards, but they showed in patches in the Rugby Championship what they can achieve, and obviously playing consistently in that competition is only going to benefit them as a team."
Wales spent the summer touring Australia, where they lost all three Tests against the Wallabies by a combined margin of just 11 points, continuing a trend of narrow defeats against the world's top three sides.
Jones added: "Australia was tough to take for us all. To end the series with only 11 points the difference across the three matches shows we weren't far away, but that is not good enough for us and we are determined to keep going.
"This team has reached the semi-finals of the Rugby World Cup and won the Grand Slam last season. After success like that there are always going to be tough times ahead as teams will be well-prepared for you.
"But we didn't drop off. We know we could, and should, have won any one of those games in Australia, and we are pushing the top teams in the world game hard.
"We have the top two teams in the world in our own back yard this autumn, and we have another great opportunity to make our mark."