Our expert bloggers will give their thoughts ahead of each game, so as Brazil prepare to host Mexico in Group A, Jack Lang (Brazil) and Tom Marshall (Mexico) are your guides.
What's at stake?
Jack Lang: Relief was the most prominent emotion after Brazil's opening day win over Croatia. Marcelo's early own goal took a nation's breath away, and only the brilliance of Oscar steadied the nerves in Sao Paulo. The result was always going to be more important in that game, but Luiz Felipe Scolari will be keen for his side to find their rhythm a little more here; a more convincing performance would set Brazil up nicely for bigger challenges ahead.
Tom Marshall Aside from the points, this match is a showcase for the entire Mexican squad. It is the most important, high-profile match for Mexico since their round of 16 defeat to Argentina in South Africa. The eyes of the world will be watching, and Mexico's players -- many of whom are looking for moves after the World Cup -- will be desperate to impress against the favorites to lift the trophy next month.
Mexico -- and their fans -- genuinely think they have a chance against a Brazil side that doesn't have the same psychological hold over them as, say, Argentina or a European giant. The memory of the Olympic final in 2012 is still fresh, and there is a feeling that Mexico -- much-improved from when these two met in the Confederations Cup in 2013 -- could make it a tricky game for Brazil.
JL: Despite his two goals, Neymar didn't quite hit the heights expected of him in Brazil's opener against Croatia. The forward was bright and busy, but there was not quite the cutting edge that we saw in the Confederations Cup this past summer. He was somewhat fortunate that Stipe Pletikosa failed to save his penalty, and he could easily have been sent off for an errant elbow on Luka Modric early in the game. Neymar will have been happy with his brace, of course, but he will still be eyeing a more complete display here.
TM: Giovani Dos Santos is half-Brazilian and speaks Portuguese, and Tuesday is the biggest game of his life. He seems ready to make an impact in Fortaleza.
The 25-year-old forward was excellent against Cameroon and would be level on two goals with Neymar had it not been for some dubious officiating. Dos Santos arrived at the World Cup after the best season of his career with Villarreal and looks ready to finally become the focal point of the Mexican national team. Very bright at finding space, Dos Santos will likely drift toward the wings regularly against Brazil, with both the host nation's full-backs, Marcelo and Dani Alves, pushing up.
JL: Oribe Peralta is the man most Brazilians will be worrying about here. It was he who put paid to the Seleção's hopes of winning gold at the Olympic Games by scoring twice to down Mano Menezes' charges at Wembley two summers ago. His determined, muscular style could pose problems for a defence that did not look especially impermeable against Croatia.
TM: Neymar is devastatingly clinical in a Brazil shirt (33 goals in 50 games), and while it might be an uninspired and obvious assertion, the Barcelona forward receiving the ball on the left with space to run at sluggish Mexican defenders Francisco "Maza" Rodriguez and Rafa Marquez is a scenario that El Tri desperately needs to avoid.
Brazil's No. 10 has already netted twice in his first game, which eased him into the World Cup. Mexico manager Miguel Herrera needs to come up with a plan to stop Brazil's star, who will be licking his lips when watching how far up the pitch El Tri's right wingback Paul Aguilar played against Cameroon. But nullifying Neymar is easier said than done.
JL: Fred versus Rafael Marquez. The Fluminense striker was quiet against Croatia; he failed to get involved with Brazil's buildup play and struggled to find space in the area. He ensured his name appeared on the back pages with a laughable dive to win a penalty but will be keen to make a more positive impression this time. His duel with the experienced Marquez could be key.
TM: Jose Juan Vazquez versus Oscar/Neymar/Hulk. A look at the heat map from Brazil's opener against Croatia showed that the host nation's attacking trio of Oscar, Neymar and Hulk were given freedom to roam and actually played quite narrowly -- likely to allow the full-backs space to overlap. Dealing with the fluidity of the trio will be key for Mexico; holding midfield Vazquez will be charged with reading the movements and plugging the gaps.
Vazquez, who was playing in Mexico's second division as recently as two years ago, will need help from Andres Guardado and Hector Herrera, both of whom need to stay compact, as well as Rafa Marquez, who could step up into midfield to counter the threat, given that Fred is Brazil's only out-and-out striker. If Oscar, Neymar and Hulk (if he is fit) do get time and space in there, the result will likely be damaging to Mexico's chances of picking up any points.
JL: Brazil 2-0 Mexico. El Tri impressed against Cameroon, but this is a different challenge altogether. Expect the hosts to claim their second win.
TM: Brazil 3-2 Mexico. A look at likely formations, styles and the players on shows that this could be the best game of the entire group stage. Don't expect Mexico to sit back. El Tri will try to take the game to Brazil in its own backyard.