Robshaw's note of caution belies the increasing sense of assuredness and confidence that has spread through England's ranks in Lancaster's near two years in charge.
Stretching back to the victory over New Zealand in December 2012, England has won eight of its last nine internationals a run that takes in back-to-back successes in a short tour of Argentina last summer, earned without its British and Irish Lions contingent. It has won its last five home games.
Victories over southern hemisphere opposition used to be rare and extremely hard-earned. Yet, last Saturday, the English often labored against Australia in their first international of the season but still ran out 20-13 winners.
"We've started this series fantastically and we need to kick on," Robshaw said. "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."
Argentina isn't so buoyant. Reeling from a chastening Rugby Championship where they shipped an average of more than 37 points a game, the Pumas have replaced coach Santiago Phelan with Daniel Hourcade, seen iconic center Felipe Contepomi retire and both captain Juan Martin Fernandez Lobbe and Juan Martin Hernandez succumb to injuries that forced them out of the entire autumn series.
Argentina hasn't beaten a major rugby nation since winning in Wales on November 2012 but Juan Manuel Leguizamon, who will captain the team in place of Fernandez Lobbe, isn't giving up hope.
"The team is very tight and our objectives are clear. People are talking about (Argentina's struggles), but we don't care,' Leguizamon said. "We are all professional players and we must adapt ourselves as quickly as possible to the new system."
As ever in games involving Argentina, one of the most powerful scrummaging units around, the front-row battle will be key.
England has overhauled its entire front three, bringing in fiery hooker Dylan Hartley for Tom Youngs and props Joe Marler and David Wilson for Mako Vunipola, who is injured, and Dan Cole.
Centers Joel Tomkins and Billy Twelvetrees struggled against Australia but are retained as the midfield pairing with first-choice Brad Barritt and Manu Tuilagi still injured.
Ben Foden comes in for Marland Yarde on the wing, while lock Geoff Parling has recovered from the effects of concussion and is on the bench.
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Lineups:
England: Mike Brown, Chris Ashton, Joel Tomkins, Billy Twelvetrees, Ben Foden, Owen Farrell, Lee Dickson, Billy Vunipola, Chris Robshaw (captain), Tom Wood, Courtney Lawes, Joe Launchbury, David Wilson, Dylan Hartley, Joe Marler. Reserves: Tom Youngs, Alex Corbisiero, Dan Cole, Geoff Parling, Ben Morgan, Ben Youngs, Toby Flood, Alex Goode.
Argentina: Lucas Gonzalez Amorosino, Horacio Agulla, Marcelo Bosch, Santiago Fernandez, Juan Imhoff, Nicolas Sanchez, Tomas Cubelli; Juan Manuel Leguizamon (captain), Julio Farias Cabello, Pablo Matera, Patricio Albacete, Mariano Galarza, Maximiliano Bustos, Eusebio Guinazu, Marcos Ayerza. Reserves: Santiago Iglesias Valdez, Nahuel Lobo, Juan Pablo Orlandi, Manuel Carizza, Benjamin Macome, Martin Landajo, Gonzalo Tiesi, Santiago Cordero.
