Hugo Lloris thinks Lionel Messi can "decide the fate of the match" if he raises his game in Argentina's World Cup last-16 match against France.
Messi offered Argentina fans a tantalising moment of brilliance with his goal as Jorge Sampaoli's men beat Nigeria 2-1 to avoid a group-stage exit.
Lloris, who earned his 100th cap against Peru before being rested for the match against Denmark, suggested France will take collective responsibility for keeping the Barcelona star in check, with a place in the quarter-finals on the line.
"We are preparing to play in a last-16 game against Argentina, so we have to be at our top level," he told reporters ahead of Saturday's match.
"We've studied their group games, which gives us an indication, but we know players like Messi can step up his own level and decide the fate of the match, as he does with Argentina and Barcelona.
"We need collective answers, to give it our all individually and collectively. We need to be outstanding to go ahead."
He added: "Argentina have a lot to prove. They've had difficult times and still qualified. I'm sure they feel like going much further in the competition.
"They've won the World Cup in the past so it will be a big, difficult match and we'll have to step up our level."
Lloris refused to be drawn on comparisons between the talismanic Messi and France's prodigious winger Kylian Mbappe.
Paris Saint-Germain star Mbappe scored France's winner in their 1-0 victory over Peru and Lloris said he expected the 19-year-old to shine against Argentina.
"Messi is unique, you can't compare anyone to him," said Lloris.
"Kylian has huge quality and potential, he's fast, explosive and needs space. I think [against Argentina] he'll have more space than the first three matches and as we go on in the competition the level will step up and will have less room for mistakes.
"Mbappe has the potential to make the difference in difficult moments."