Estimated read time: 3-4 minutes
Croatia's 20-year-old Joško Gvardiol and 25-year-old Nikola Vlašić, plus Belgium's 21-year-old Charles De Ketelaere, are some of the exceptions — with Belgium's 21-year-old midfielder Amadou Onana suspended for the game after picking up two yellow cards.
Nicknamed "Little Pep" because of the similarities between his last name and that of Manchester City coach Pep Guardiola, the physical Gvardiol has already become a fixture at center back for Croatia and Leipzig, which recently extended his contract to 2027.
Despite the contract extension, Gvardiol has been linked with a possible to transfer to Chelsea, where he could join Croatia teammate Mateo Kovačić.
"At the age of 20 he has demonstrated that he can play at a great level," Kovačić said. "He just needs to continue doing that."
Nikola Vlašić, the younger brother of former high jump world champion Blanka Vlašić, usually plays as an attacking midfielder. But on a Croatia team featuring the likes of Luka Modrić, Marcelo Brozović and Kovačić in midfield, Vlašić is used as a winger.
Statistically one of best midfielders in Serie A this season with Torino, where he is on loan from West Ham, Vlašić is often involved in the buildup to goals and also puts a lot of shots on target.
Vlašić exited Croatia's opening 0-0 draw with Morocco at halftime after picking up a knock, but returned as a substitute in a 4-1 win over Canada.
"Everyone thinks about the three midfielders, and rightly so, but this team now carries even more threat," Belgium coach Roberto Martínez said of Croatia.
"(Croatia coach Zlatko Dalić) highlights new players that are coming in around those three players."
Belgium also relies on a veteran attacking core of Eden Hazard, Kevin De Bruyne and Romelu Lukaku — who hasn't been 100% physically — in attack, meaning that the baby-faced De Ketelaere, or "CDK" as he's referred to, has only played off the bench so far at this tournament.
But De Ketelaere impressed upon his arrival at Italian champion AC Milan in August, drawing comparisons to former Rossoneri standout Kaká for his dribbling ability and precise crosses in the playmaker position.
"Some of the young players that haven't been in the game, they are growing behind the scenes. I can feel that they can be called on when needed," Martínez said. "I thought the players that came on against Morocco, they did their jobs, they performed well."
Croatia can secure a round-of-16 spot with either a win or a draw, while Belgium needs to win to be sure of advancing.
Croatia and Morocco lead Group F with four points each, Belgium has three points and Canada has zero and is already eliminated.
If Canada beats Morocco, it's possible that both Croatia and Belgium will advance.
"It's very difficult to go into the game looking just for a point — that's not our mentality," Vlašić said. "We need to go for a win because if you just look for a point, you concede a goal and you are in panic mode all of a sudden. So we are going for the win."
Andrew Dampf is at https://twitter.com/AndrewDampf