I don't understand why Nigeria played 4-4-2 with 2 banks of four when defending. This just allowed the Argentina players, especially Messi, to just play between the spaces.
The back four for Argentina looked susceptible as well. Jonas lacks anticipation and geniune technique and with him going forward there was a chance to exploit. Also the centre backs are slow and Demichelis likes to go straight to the ball as a "stopper" sort of player. Nigeria could've exploited this by using a fast striker and someone with his back to the goal who holds up the ball. Demichelis would be drawn out of position by the "target man" and then could play it through the gap for the fast striker to run on to who would most probably outpace Samuel. So yeah, there was an opportunity for Nigeria but they seemed to waste it. Martins was brought on quite late so had little impact, but forced Romaro to make his only real save, and the left winger (forgotten his name) came on and exploited Jonas but lacked a good cross.