Many believe this will be an easy match for Argentina but Fulham's Ashkan Dejagah will be key to any chance Iran have. Who stops Barcelona superstar?
Ashkan Dejagah v Pablo Zabaleta
The Fulham midfielder struggled in Iran's opener against Nigeria, as he failed to complete any more than half of his passes. He started that match in the number 10 role just behind the striker, but don't be surprised if Carlos Queiroz puts five across midfield as he looks to pack the midfield with players, limiting the space for the Argentine attack.
If that is the case, he is likely to face Man City defender Pablo Zabaleta, who this time will likely be the right back of a flat back four. Zabaleta will still have the freedom to get forward and overlap his forwards, thus leaving plenty of space behind him. This is the only clear area of the pitch where Iran could enjoy some attacking threat of their own, and if they do so, they will need Dejagah to have the match of his life to get the better of Zabaleta and the rest of the Argentine back four.
Jalal Hosseini v Lionel Messi
Hosseini is the experienced defender in the Iran back four. It will be his job to organise the defence and look to keep out one of the most potent strike forces in the world. His job may well be to mark Lionel Messi, who scored a superb individual goal against Bosnia at the Maracana on Sunday.
It would be understandable if Hosseini would be star struck playing this Argentine forwards, but he can't be if Iran are to shock the footballing world and get something in this match. He will need plenty of help to stop Messi, but ultimately it could be Hosseini who is left to mark Messi out of the game, if that is possible..
Amirhossein Sadeghi v Kun Aguero
Iran's other centre back is Sadeghi, like Hosseini, he plays in Iran's Premier League. He will be likely to mark a striker who plays in the Premier League, not the Iranian one, but the English one, and for the champions Manchester City.
It is expected Argentina are going to put Aguero, Higuain and Messi up front together in a 4-3-3 formation, and that is likely to cause Sadeghi nightmares tonight. If that is the case, Sadeghi will need to mark Aguero out of the game, as the Man City striker will be confident he can open his World Cup account in Belo Horizonte on Saturday.