Our expert bloggers will give their thoughts ahead of each game, so as Nigeria take on Argentina in Group F, Colin Udoh (Nigeria) and Sam Kelly (Argentina) are your guides.
What's at stake?
Colin Udoh: For Argentina, first place in the group will see them skip fellow heavyweights France in the round of 16, meaning that they will want to play for at least a draw to give them that assurance. It's a little trickier for Nigeria. They did the hard job of eliminating Bosnia-Herzegovina, but still have to look over their shoulders at Iran, who could upstage them with victory in the other game. Then there's the small matter of having faced and lost to Argentina at three previous World Cups. This might be a young and inexperienced Nigeria team, but they are hungry to leave their mark and an Argentina scalp would be one to hang in the trophy room.
Sam Kelly: This match has become something of a regular fixture lately; the sides have met just six times at senior level, but all those meetings have come since USA 1994. In 1994, 2002 and 2010 they were drawn in the same group; they also met at the 1995 Confederations Cup, and played two friendlies in 2011.
Argentina have won four (including all three previous World Cup meetings), and there's been one draw. The sole Nigerian win -- a 4-1 victory in one of the friendlies -- was later investigated by FIFA due to suspicious betting patterns.
CU: Emmanuel Emenike was in beast mode against Bosnia-Herzegovina. Such was his brute force, power, pace and skill that Bosnia-Herzegovina captain Emir Spahic couldn't live with him and required tag team assistance every time Emenike came bearing down that channel. And it was that sheer force of physical strength that wore down the Bosnians in the end and created the chance for Peter Odemwingie to finish. Against Argentina, Emenike is expected to be in similarly uncompromising mood. He is yet to get a goal and that is more than enough motivation for the striker.
SK: Marcos Rojo. Singled out by many -- myself included -- as Argentina's weak link before the tournament, he's looked rather good in the opening two matches, and was arguably man of the match against Iran. Can he keep up the impressive performances against a side that will be expected to provide more of an attacking threat than Iran did? Can one of the forwards finally get on the end of one of those tempting crosses he keeps putting in?
CU: Who else but Lionel Messi. This is looking to be his World Cup. Having failed at the previous edition in South Africa, the little genius appears to have set his stall to put his mark on this edition. Two spectacular goals in two games provide evidence enough. And then he has extra motivation. Frustrated by Vincent Enyeama four years ago, the Barcelona superstar will want to redress that imbalance. But then there's his supporting cast: Gonzalo Higuain, Sergio Aguero and Angel di Maria. There will be plenty there to keep the Nigeria defence more than occupied and then some.
SK: Peter Odemwingie. Man of the match against Bosnia-Herzegovina when Nigeria won 1-0 to ensure they'll qualify with just a point from this match, Odemwingie's form picked up after his move from Cardiff City to Stoke City for the second half of last season. With Argentina coming into the match two points ahead in the group table, the Russian-born striker will know he has to take his chances if he's to give his side hope of topping the group.
CU: Hard to look past a continuation of the slugfest from 2010: Vincent Enyeama against Messi. Four years ago, the Nigeria goalkeeper was unyielding against Messi & Co., leaving the Argentine so frustrated that he described Enyeama as a "phenomenon." Three FIFA Ballon d'Or awards later, Messi will want to test if Enyeama has progressed as much as he has. There'll be other battles too. Defender Kenneth Omeruo, who has shut out the likes of Edin Dzeko, Luis Suarez and Edinson Cavani, among others, would like to use Messi or any of his cohorts as the cherry on top. Success will send his market value skyrocketing, and probably put him straight into Jose Mourinho's first team at Chelsea.
SK: Lionel Messi vs. Vincent Enyeama. Those who were surprised by Enyeama's good showing against Bosnia-Herzegovina clearly didn't remember Nigeria's World Cup campaign in 2010. His performance against Argentina in their group showdown four years ago is seared into the collective consciousness; six fine saves kept Argentina at bay after they'd opened the scoring very early on through Gabriel Heinze -- that ended up being the only goal of the game. Four of Enyeama's brilliant saves were from Messi. Here, the forward will have a chance to get revenge.
CU: Nigeria have been as miserly in front of goal as they have been stingy at their own end. Argentina have not been particularly prolific either, and a draw would suit both sides. Score: 1-1.
SK: I'll go for 2-0 to Argentina. They haven't hit their stride yet, but Messi has stepped up at key moments. Unless Nigeria try to play things the same way Iran did, Argentina will surely have a bit more space to play with in and around the penalty area.