United States striker Chris Wondolowski has likened replacing team-mate Jozy Altidore to filling in for Portugal's Cristiano Ronaldo.
Jurgen Klinsmann's men face Portugal in Manaus on Sunday knowing that a win will see them qualify for the last 16, providing that Ghana drop points against Germany on Saturday.
However, the USA will be without Sunderland forward Altidore due to a strained hamstring suffered in the 2-1 win over Ghana on Monday.
It remains to be seen who will take the place of Altidore should he be unable to play, although a pairing of Wondolowski and AZ's Aron Johannsson has been mooted.
But for San Jose Earthquakes star Wondolowski, the prospect of coming in for Altidore is a daunting one.
He explained: "Jozy is a special player – that's like saying 'Hey, go be Cristiano Ronaldo'.
"You can't necessarily replace certain aspects of it, but I think that both Aron and I bring different styles, different sets of skills that I think are useful.
"And I think that's what we have to go do is incorporate those skill sets, and fit into the game plan as well.
"We're going to have to do certain things that Jozy did, and incorporate our styles as well."