Our expert bloggers will give their thoughts ahead of each game. As Germany take on Portugal in Group G, Stephan Uersfeld (Germany) and Simon Curtis (Portugal) are your guides.
What's at stake?
Stephan Uersfeld: Germany and Portugal have met three times in the past two World Cups and two European Championships, and Joachim Loew's team won all three. But it was at Euro 2000 when Germany lost 3-0 to Portugal to crash out of the competition, thus setting the path for important changes in the DFB. The current crop of players is the reward of that, and it goes into this fixture as a slight favourite.
Both nations hope to avoid a defeat in the opening match at any cost, with the United States and Ghana both capable of upsetting the group favourites in the upcoming games. Loew praised Portugal as the best counterattacking side in the world and has said that the Nationalmannschaft will storm out of the dressing room to change the course of the game.
Simon Curtis: As a World Cup group opener, there could hardly be more at stake. There are a number of sizzling opening games in the World Cup 2014 group stage -- England vs. Italy and Netherlands vs. Spain among them -- but Portugal vs. Germany pits two countries together with realistic hopes of a place in the last four. Neither will be happy to start the tournament with a defeat.
Paulo Bento's men will be hoping to emulate their Euro 2000 compatriots, who managed a 3-0 win over a stuttering German side before going out to France in a never-to-be-forgotten semifinal. Either way, this is likely to be the most difficult group game for both contenders.
SU: Mario Goetze, though you will probably find him on the bench to start, as he is destined to be Loew's weapon in the second half. After a less-than-stellar Bundesliga season, Goetze appears to be in good shape ahead of the World Cup.
The 22-year-old Bayern Munich attacker scored twice in the final warm-up against Armenia when he came off the bench, and he has eliminated a certain wastefulness in front of the goal. While he might lack speed, he is a revelation on the ball and is one of the key players in Loew's squad.
SC: Who will start up front for Portugal? This has been a burning question for some time and indeed has been a problem position for the national side since Pauleta left the scene after the 2006 World Cup. Bento has tried Braga's Eder and Lazio's Helder Postiga, whose goal-scoring record for Portugal is less poor than people give him credit for, but neither has shone.
The fact that the giant Hugo Almeida not only scored a brace in the final warm-up against Ireland but also enjoyed five successful seasons in the Bundesliga with Werder Bremen means he is likely to start and will be asked to continue where he left off against the Irish. If the rejuvenated Nani continues his pre-World Cup form, the service will be there for him.
SU: Cristiano Ronaldo. It's just too obvious. Germany indeed fear the Real Madrid forward more than any other player in the group stage.
Loew will play Bayern Munich centre back Jerome Boateng at right back to stop the Portuguese goal-scoring machine, but the Nationalmannschaft know that Ronaldo will not be stopped by a single player. In the past, Germany have had problems stopping the passes in midfield, and they will need to control the middle to ease the burden on the defence.
"He creeps into the dead angle, gets blind passes from his teammates. You are never allowed to lose sight on him," Loew said. "Whoever plays him must know where Ronaldo is, what he does all the time."
It will take a team effort to track the Real Madrid star, should he return to form following his ongoing knee problems.
SC: Where to start? The German side is packed with quality from goalkeeper right through to the front line, but 2010 World Cup top scorer Thomas Mueller is perhaps the best player in the Bundesliga right now and will be a real handful for Bento's defence. Bruno Alves and Pepe will have to be at their best to keep the German attack out, and Mueller's deceptive running off the front line will cause plenty of headaches.
SU: Benedikt Howedes vs. Nani. While the focus might be on the other wing, the duel between makeshift left back Howedes and Nani could be as important as the Boateng vs. Ronaldo battle.
Following an unspectacular season at Manchester United, Nani returned to form in Portugal's recent friendlies and will face Schalke 04 captain Howedes, a learned centre back who has played at right back before but is mostly untested on the other side of the pitch. Like with Ronaldo, Germany must prevent diagonal passes in midfield. While the most exciting battles might take place on the wing, Germany need to work defensively as a unit to stop Portugal.
SC: Ronaldo's battle with the somewhat statuesque German defence is likely to be crucial. His increasing good health after a number of days of worrying injury troubles means the Portuguese superstar will be ready to wreak havoc on any weaknesses on offer in the German rearguard. With the likes of Per Mertesacker and Boateng sure to be present, with the latter likely keeping tabs on Ronaldo's movements, there could be rich pickings for the world player of the year.
SU: Germany 2, Portugal 2. Germany hope for a good start, and while a draw against Portugal will pave the way for a solid qualification from their group, critics in Germany will not be silenced. Ah, that defending.
SC: I agree with Stephan. If everyone plays as they did against Ireland last weekend, Portugal will prove to be a proper handful for any opponent. With the Germans tipped to still be playing in a month's time, this is undoubtedly a big one for both sides. A thrilling, sweeping 2-2 draw that will set them both up for qualification awaits us.