Our expert bloggers will give their thoughts ahead of each game, so as Colombia take on Greece in Group C, Carl Worswick (Colombia) and Chris Paraskevas (Greece) are your guides.
What's at stake?
Carl Worswick: Colombia have waited 16 years for this game, and on the back of an impressive qualifying campaign, hopes are high that they can fare better than in their two previous finals appearances (group-stage exits in 1994 and 1998). Injuries to key players and fitness concerns have besieged their World Cup preparations, but the side is still packed full of exciting attacking talent that should -- for now -- cover up for the cracks at the back.
With Colombian fans expected to vastly outnumber their Greek counterparts in Estadio Minerao, the Group C opener should feel almost like a home game for the South Americans, who will be strong favourites to kick their Brazil campaign off with a win. But the team has had to deal with intense strain of expectancy in the past, and anything other than a victory here will only ramp up the pressure to insufferable levels.
Chris Paraskevas: Greece's entire campaign rests on this game. If they don't at least get a point, they are virtually certain to be heading home at the end of the group stage. Beyond that, a first draw or victory against a South American side at a major tournament would be a huge psychological boost for this group of players.
There's everything to lose and everything to gain on Saturday, as far as Greece are concerned.
CW: One of Jose Pekerman's first tasks upon becoming Colombia manager two years ago was to hand then 20-year-old James Rodriguez the fabled No. 10 shirt once worn by Carlos "El Pibe" Valderrama. For a player who had only just made his senior team debut, it was considered a bold gamble. But it paid off. Despite his tender years, Rodriguez thrived under the pressure as he finished the qualification round as one of Colombia's key players.
Against Greece's stubborn back line, there's every reason to believe that the Monaco frontman's guile, leadership and eye for a decisive pass could be the difference. Colombia expect a lot from their young star, and the 2014 World Cup could be his big moment.
CP: Ioannis Fetfatzidis. Much has been written about Kostas Mitroglou's form and fitness (or lack thereof) in the lead-up to this tournament. While the Fulham man is important to Greece, Fetfatzidis showed in the friendly matches that he's hungry and extremely talented.
The 23-year-old is coming off a successful debut season in Italy and is unafraid to take on his marker. He offers something this Greek team conspicuously lacks: unpredictability. It's likely he'll start off the bench against Colombia but he could be the man to make the difference in a tight contest.
CW: The clock. If time drags on and Colombia are unable to find a way past Greece's tight defence, then mounting pressure could be their undoing. The big fear is a repeat of 20 years ago, when the country's golden generation arrived at the U.S. finals as one of the favourites, only to suffer a devastating blow in losing to Romania in their first game.
Against Group C's weakest team, everyone again expects three points, but if Greece are able to stifle and suffocate Colombia's creative forces, then nagging doubts from yesteryear may again resurface. An early goal will be crucial to extinguishing those nerves.
CP: Carlos Bacca's natural ability to get on the end of crosses in the penalty box will be a big threat to Greece. The two centre-backs will really need to keep an eye on the Sevilla forward, who is coming off a sensational season in Spain. He starred in the Europa League and was excellent in La Liga and he combines athleticism with a natural instinct for goal. His ability to play off the shoulder of the last man could be unsettling.
CW: Juan Guillermo Cuadrado versus Jose Holebas. The Fiorentina winger is at the top of his game and looks to have finally cut out the annoyingly wasteful elaboration he was once guilty of. Blessed with pace, skill and a sweet strike, the 26-year-old has the ability to effortlessly glide past his marker. As creator or marksman, Cuadrado is deadly, and up against opposite number Holebas the stage is set for the wideman to wreak havoc. Holebas is the weak point in the Greek back line. Once a forward but now crowbarred into a wingback role, doubts about the German-born player's defensive input will surely be exploited by Cuadrado's quick feet.
CP: I agree with Carl, it's Cuadrado versus Holebas. Cuadrado is one of Colombia's main attacking weapons and Holebas is Greece's biggest weak link. The Greek left-back will face a stern test up against Colombia's right-winger, who is quick, direct and very skilful.
Holebas has a tendency to get caught out of position and give up possession cheaply, and you can be certain that Cuadrado will love running at the Olympiacos defender. This is Greece's Achilles' heel.
CW: Colombia 2, Greece 0. The South Americans simply have too many attacking options and will come out hungry looking for an early goal. Even if Greece are temporarily successful in frustrating Colombia, Pekerman has players like Victor Ibarbo and Juan Fernando Quintero who are capable of changing the game from the bench.
CP: 1-1. I really do think this will be a cagey affair, with the Greeks set to frustrate the Colombians, who might take a bit of time to hit their stride, given Radamel Falcao's absence because of a knee injury. If he were still playing, this prediction would be rather different.