Our expert bloggers will give their thoughts ahead of each game, so as Uruguay take on Costa Rica in Group D, Felipe Miguel (Uruguay) and Matt Levin (Costa Rica) are your guides.
What's at stake?
Felipe Miguel: Many will remember when they played against each other in the intercontinental qualification playoff for the 2010 World Cup, which led to Uruguay qualifying for South Africa. Both legs were great football battles, and Costa Rica were very close to causing a shock. Although we can't speak of an existing rivalry between Los Ticos and La Celeste, it's probable that Costa Ricans are hungry for revenge and will play their hearts out on Saturday. Uruguay must win if they want to have a real chance of going through because it is unlikely that they can defeat both England and Italy. As Uruguay midfielder Egidio Arevalo Rios said, Costa Rica have nothing to lose so they will risk everything to see if they can secure three points.
Matt Levin: Uruguay, despite being one of the few countries in the tournament with a smaller population than Costa Rica (3 million to 4.5 million), are football giants and Costa Rica have never beaten their Latin American counterparts -- in 10 matches, the Ticos have seven losses and three draws. In terms of recent history between the two, they last met five years ago, battling for the last spot at the 2010 World Cup. Uruguay won the play-off en route to a fourth place finish in South Africa. As England and Italy slug it out in soggy Manaus, Uruguay will be eager to take control of Group D. Underdogs Costa Rica hope their first victory against La Celeste will come on football's biggest stage.
FM: Although the obvious pick would be Edinson Cavani, if Uruguay can't create chances for him, they lack options and look naïve, especially with Luis Suarez likely to be rested. Cristian Rodriguez has been one of the major weapons for La Celeste's attack, running back and forth through the left side and delivering precise crosses to the strikers. Rodriguez cannot stand still when his side are struggling. Like a human bulldozer, he will power his way through anything in his wake to help his team get on track.
ML: Joel Campbell. The 21-year-old forward sounds pumped for his World Cup debut and is determined to prove his scoring prowess in a group featuring superstars Suarez, Mario Balotelli and Wayne Rooney. Campbell has added motivation in that a strong performance here could place him with Arsenal next season. He signed for them in 2011, but has remained on loan ever since.
In Costa Rica's final friendly before Brazil, Ireland couldn't contain for Campbell's speed and craftiness. If Costa Rica can get on the ball, they'll look to Campbell for inspiration.
FM: Costa Rica's man to watch must be Bryan Ruiz. The talented left-footed forward has been their key man for quite a few years and his Premier League and Eredivisie experience is invaluable to Jorge Luis Pinto's side. Uruguay must not allow Ruiz to take advantage of an often unprotected right side, where Gaston Ramirez and Christian Stuani are very attack-focused and Maximiliano Pereira tends to go forward as much as he can. If Ruiz finally starts through the right side like he did against Japan, Martin Caceres and Diego Godin will give him little room to play inside the box.
ML: Suarez, if he plays. Knee surgery less than a month before the World Cup meant Suarez has had to heal quickly to make opener. Whether he is 100 percent fit for this one is uncertain. In any case, La Sele goalkeeper Keylor Navas said it wouldn't matter much if Suarez didn't play because Uruguay have great forwards available to take his place. He's right -- Diego Forlan and Stuani are no slouches. But Suarez's absence really is the difference between decimation for the Ticos and a slim chance.
FM: Cavani v Navas. It's the Matador versus the Falcon.
Many Uruguayan players that have spent time at Spanish La Liga must have surely advised Cavani on how to beat Navas. "El Matador" has scored against some of the best keepers on the planet throughout his career but Navas is a confident stopper who has enjoyed a fine season at Levante. The man of the match is probably going to be one of these two: either the goal-scoring star or the shot-stopping saviour.
ML: Cavani and Suarez (or whoever replaces him) v Costa Rica's defence.
Giancarlo Gonzalez and company were a force to be reckoned with back in qualifying. Alas, matches in CONCACAF don't do much to prepare you for an attack like the one Uruguay have. Moreover, the defence looked shaky in last week's World Cup warm-ups against Ireland and Japan. The unit endured another blow on Tuesday when Heiner Mora, amid competition to start at right back, was declared out of the World Cup due to a micro-fracture in his right heel.
If the Ticos don't correct what went wrong last week Uruguay's forwards could end this game in a hurry (and doubly so, if Suarez plays).
FL: I have got to stand by Uruguay on this one. Costa Rica have had too many major injuries and many of their players perform in inferior domestic leagues. Uruguay's overconfidence can play against them but in the end they will probably take the three points. Uruguay 2-0 Costa Rica.
ML: I'm going to say Uruguay to win 2-0 as well. They have too much firepower even with a top player missing from the line-up and Costa Rica, even with Campbell, just don't have enough.