Argentina are seen as the class of their group, which includes Bosnia-Herzegovina, Iran and Nigeria. But that's on paper. The real action starts today, with La Albiceleste seeking to get on the right path.
We've seen how even pre-tournament favorites such as Spain have come out of the gates slowly. But so far, South American teams have upheld their reputation of playing well when the host is in South America - with the notable exception of Uruguay. But will Argentina, Brazil's biggest rival, enjoy any "home" advantage?
Lionel Messi will start, and all eyes, of course, will be on him. Already, Alexis Sanchez and Neymar have scored for their respective countries and it'd be natural to assume that the best part of Barcelona's front three would get on the score sheet.
However, Messi is being tasked with providing the creativity in the side, and it's not unthinkable that Argentina will go far with him providing more assists than goals. He's being deployed as a mix of a playmaker and scorer, and his understanding with his striking partners is paramount to get the most out of such an unorthodox frontline.
However, Argentina may be handicapped somewhat. Rodrigo Palacio, who was excellent in the friendly against Trinidad and Tobago, has not recovered fully from a knock and is not expected to be available for the match - at least not from the start.
Meanwhile, Gonzalo Higuain did not participate in any friendlies as he was recovering. Hopefully, he will be fine, but if not, Argentina will, unexpectedly, be a little short on forward talent.
Given that Sergio Aguero is now quite likely to start, the only remaining forward is Ezequiel Lavezzi.
In training, coach Alejandro Sabella tried two formations. The first was a 4-3-3, keeping the same system the team has been expected to play. Aguero can take Higuain's place as the furthest forward, while Lavezzi can take more of a support / wing role, the spot Aguero vacated.
The other formation is a 5-3-2, with Messi and Aguero the forwards. This formation gives a bit more security, and is more likely to be used if Higuain is not ready. Lavezzi could remain an option from the bench.
Sabella deployed both formations in training, having his first choice XI practice against his backups. Higuain was included as part of the backups, trying to replicate Dzeko's role in a 4-4-1-1. Sabella was trying to figure out which formation would cope better.
"The Sloth", an assistant coach for Argentina during France 98, recently said the main lesson he learned from their elimination was the importance of rest. Considering this, it's plausible that Sabella will keep Higuain away unless absolutely necessary.
Therefore, it's not improbable that he may start with the 5-3-2 before moving to a 4-3-3 with the introduction of Higuain if is side need a goal.
After all, a 5-3-2 Argentina without Messi or Macherano downed Bosnia 2-0 in a friendly last year. Sabella was mum on which formation he would choose.
Sabella has been using the 5-3-2 formation as an alternative nearly as long as he's been in charge. It's not surprising at all that he is considering it for some situations this tournament.
While on its face, the 5-3-2 is more defensive as it takes off a forward for a defender, this is mitigated somewhat by using only a single holder.
In the end, injuries to two strikers plus fitness concerns over Gago may make Sabella opt to field a formation that does not require them.
There is some logic in an extra central defender given the opponent, as well. It's no secret that Bosnia's best 3 players are Manchester City's striker Edin Dzeko, Roma midfielder Miralem Pjanic, and goalkeeper Asmir Begovic of Stoke City.
Dzeko and Pjanic play centrally and high up the pitch, so sacrificing a player to pack the middle with an extra defensive option has its advantage. The problem though may be over-focusing on Dzeko in particular.
There may not be enough width in attack with Marcos Rojo and Pablo Zabaleta not exactly Dani Alves.
Possible XI: Romero; Rojo, F. Fernandez, Garay, Campagnaro, Zabaleta; Maxi Rodriguez, Mascherano, Di Maria; Messi, Aguero (5-3-2)
Alternative XI: Romero; Rojo, F. Fernandez, Garay, Zabaleta; Gago, Mascherano, Di Maria; Aguero, Higuain (or Lavezzi), Messi (4-3-3)