Manchester United midfielder Nemanja Matic said Thursday his Serbia side were ready for a "hellish" clash against Switzerland in a crunch Group E encounter tinged with political tension.
The Serbs control their destiny after an opening 1-0 win against Costa Rica on Sunday, which came courtesy of a stunning Aleksandar Kolarov free-kick.
But Friday's game could decide the eventual shape of Group E, with both sides vying for what is likely a single last-16 spot alongside five-time winners Brazil.
"We are aware of what is in store for us," Matic said. "They have qualities throughout the squad, excellent individuals. We expect a hellish game but we are going to be ready for anything."
Swiss coach Vladimir Petkovic has vowed to keep up his side's high-tempo, physical approach that earned them a draw with Brazil.
Switzerland fouled Neymar 10 times during Sunday's 1-1 stalemate -- the most inflicted on a single player in a World Cup game since 1998 -- and Petkovic said his side would not hold back against the Serbs.
"We can't just play physically," he said. "We also have to outrun our opponents and I believe also that we have to play our own football."
Serbia boast a host of current and former Premier League talent, including Matic, Kolarov and Newcastle forward Aleksandar Mitrovic.
But their rising star is Lazio's Sergej Milinkovic-Savic, a rangy attacking midfielder who has drawn comparisons with Serbian great Dejan Stankovic.
Former coach Slavoljub Muslin, who led the team to qualification for Russia, reportedly paid with his job for failing to select Milinkovic-Savic.
It is not a mistake current coach Mladen Krstajic intends to repeat and the Lazio man -- who has reportedly attracted the interest of Real Madrid -- was lively against Costa Rica.
"I guarantee you my players will take responsibility, be aggressive and on top of the other team," Krstajic said Thursday.
"They (Switzerland) are a tactical and technical side that has been together for a long time," he added. "It's going to be a fierce match tomorrow."
- Kosovo question -
Serbia have based themselves in Kaliningrad -- Russia's remote territory on the Baltic Sea -- for the tournament and tens of thousands of their countrymen are expected to travel for the game.
One sub-plot to watch out for could be the Serbian fans' treatment of Switzerland's three players with links to Kosovo.
Midfielders Valon Behrami of Italian club Udinese, Xherdan Shaqiri of Stoke City and Arsenal's Granit Xhaka all have Kosovar heritage and all three played in the Brazil game.
Shaqiri took to the field for the match with a Kosovan flag on one of his boots, and the trio are likely to get a hostile reception from a Serbia-dominated crowd.
Kosovo was a former province of Serbia, and Serbian fans gathered in Kaliningrad Tuesday to celebrate Russia's 3-1 over Egypt while chanting "Kosovo is Serbia."
Neither coach would be drawn on the issue Thursday, with Krstajic saying he is "not interested in politics."