Lionel Messi is joined by Sergio Aguero and Napoli striker Gonzalo Higuain, as Argentina change shape for Iran.
It kicks off at 17.00 UK time in Belo Horizonte with progress in Group F at stake.
Argentina won their opening match 2-1, but it was more than a little difficult to break down Bosnia.
Messi was poor for most of the game until a moment of magic secured his first World Cup goal since 2006.
The Barcelona hero will have all eyes on him again today against an extremely organised Iran side.
Carlos Queiroz’s Iran held Nigeria to a bore draw and will attempt to stifle the Albiceleste team too.
The only previous encounter between these teams was a 1-1 friendly in Madrid in March 1977.
Argentina were criticised for fielding a 3-5-2 formation against Bosnia last week, but they improved considerably after switching to 4-3-3 with Higuain coming off the bench.
Coach Alejandro Sabella took the hint and now starts with that system and the Napoli forward.
Argentina: Romero; Zabaleta, Garay, F Fernandez, Rojo; Gago, Mascherano, Di Maria; Messi, Higuain, Aguero
Iran: Haghighi; Hosseini, Sadeghi, Montazeri, Pooladi; Dejagah, Timotian, Nekounam, Haji Safi; Shojaei; Ghoochannejad
Think you know your Italian football? Share your knowledge, tips and comments to win cash prizes in OLBG's tipster competition - £11,000 to be won monthly!