England captain Chris Robshaw feels Argentina will provide his side with a stern test in the second QBE International at Twickenham on Saturday.
Robshaw's men began their autumn campaign in fine style last weekend with a second-half rally proving enough to secure a 20-13 win over Australia.
A week on, it is another Rugby Championship powerhouse arriving in London, and Robshaw feels the Pumas have changed their outlook on the game since taking on Australia, New Zealand and South Africa in the southern hemisphere tournament.
"There are a lot of differences," Robshaw said ahead of coach Stuart Lancaster naming his XV to face the Pumas. "Argentina are traditionally known for their strong scrum, physical forwards, physical back, but I think you've seen in the last two years how much they've developed going into the Championship.
"They've got a much more free flowing game, they tested the kind of three or four best teams in the world. It will be a massive challenge for us."
Robshaw sees momentum as key to the way his side has been performing, and with New Zealand looming seven days later, he is keen not to let that wane while trying not to take the focus off the undoubted challenge the Pumas will provide.
"We've started this series fantastically and we need to kick on," he added. "We got some huge momentum, beating Australia for the first time myself. We know now what it takes to beat one of the southern hemisphere sides.
"I think whenever you go into a series you want to get off to a win first and foremost then you build on the performance. Of course you always want a perfect performance but you'd rather take a win I think.
"As pro players and athletes you focus on the next game. As soon as you take a team like Argentina lightly then you're in a world of trouble. You need to make sure you're professional in everything you do, keep improving as a team and make sure you get the right result.
"I think you look at New Zealand as kind of the No 1 team in world rugby, they have such a big squad that they can rest two or three players every week and bring other players in who are equally as good.
"That's what you need, that competition. I think we are developing that. Our loose heads all the way back to our No 15s, we've got two or three players in each position that if any one of them came in you'd be pleased to have them in your side.
"It probably is a bigger selection headache for the coaches but as a squad if we want to be out there getting better and improving we need to have a number of players in each position which we're fortunate enough to have at the moment."
Watch England take on Argentina live on Sky Sports 2 and Sky 3D, coverage starts at 1.30pm on Saturday