Croatia midfielder Ivan Rakitic said there would be no favourites in the quarter-final match between Russia and Croatia.
Russia defeated Spain 4-3 in the penalty shootout after being held to a 1-1 draw in 90 minutes and extra time on Monday (AEST).
Croatia also drew 1-1 with Denmark, but the team won 3-2 on penalties and set up a World Cup quarter-final game with the tournament hosts.
"The match between Russia and Spain has shown that everything is possible at the World Cup," Rakitic said.
"A grand quarter-final match, which won't have favorites, is awaiting for us. But we are able to reach the semi-final."
The Russia and Croatia match-up will be held at Sochi's Fisht Stadium on Sunday (4am AEST).
The 2018 FIFA World Cup kicked off on June 14 and will continue until July 15, with the matches being played in 11 cities across Russia.