Eddie Jones will not consider resting key players for England's final Pool C fixture against "impressive" France, despite already securing a place in the quarter-finals.
England eased past 14-man Argentina on Saturday, with a 39-10 result at Tokyo Stadium securing them a third straight bonus-point win at the 2019 Rugby World Cup.
They are now certain to go through from the group with a game to spare, though potentially face a showdown with France next Saturday to decide who will finish top of the table.
Les Bleus have also beaten Argentina and Jones expects a tough battle in Yokohama, particularly as their Six Nations rivals have seemingly gone back to their roots since Fabien Galthie joined the coaching staff.
"They [France] were impressive in the first game against Argentina," the England head coach told the media after the game with the Pumas.
"They played some great rugby and got two unstructured tries at the start of the game.
"They look like, with Galthie having an influence in their coaching, they are getting back to more of their game, a little bit of an offload and support game. We are going to have to work very hard defensively against them.
"The set-piece is always challenging against France, they have a particularly big team, so our preparations have to be spot on."
England know top spot will see them face the second-placed team in Pool D, which - if results run true to form - will be Australia. Yet Jones is only focused on France - and has no intention of letting his squad's standard slip.
"We are building. We want to get better next week. We will have a look at selection and pick the best 23 to get better," the Australian said.
"We don't want to look too far ahead - that's for you guys [in the media]. We don't get the luxury of doing that.
"We just worry about one day at a time. We've got to make sure we have a good recovery tomorrow and a walk-through, then we worry about the next day."
Billy Vunipola came off at half-time against Argentina and while initially joking it was due to too much Kobe beef, Jones revealed the forward had likely suffered a twisted ankle, adding: "I don't think it's too serious."