FIFA world ranking: 5.
Last World Cup: 2010.
Best World Cup finish: Two-time champion (1978, '86).
How qualified: CONMEBOL round-robin winner.
It's a fact: Fans in Argentina credited "divine intervention" on the part of Buenos Aires-born Pope Francis – a fervent soccer fan – for the country being drawn into what appears to be the softest of the World Cup's eight groups.
The skinny: Although its national team includes one of the best players in history in Lionel Messi, Argentina hasn't won a major championship since capturing the Copa America in 1993 when Messi was 6. Messi needs a World Cup title to secure his legacy and, playing in neighboring Brazil, he'll lead a team so explosive coach Alejandro Sabella will use a 4-3-3 setup to get forwards Sergio Aguero and Gonzalo Higuain on the field with him. The midfield, anchored by playmaker Angel di Maria, and back line, led by attack-minded Pablo Zabaleta, can be exploited, though, especially if too many players push too far forward.
FIFA World ranking: 21.
Last World Cup: First appearance.
Best World Cup finish: First appearance.
How qualified: UEFA Group G winner.
It's a fact: Bosnia-Herzegovina, the only team making its World Cup debut this summer, will be the 77th country to appear in the tournament.
The skinny: Bosnia narrowly missed qualifying for the 2010 World Cup and 2012 Euro, losing twice in playoffs with Portugal. So after going 8-1-1 in UEFA qualifying this time around, outscoring opponents by 24 goals to win its group and a spot in its first World Cup as an independent nation, more than 50,000 fans welcomed the team home to Sarajevo. With Manchester City's Edin Dzeko and former St. Louis University All-America Vedad Ibisevic up front, Bosnia can score in bunches. But the lack of a solid holding midfielder leaves its defense vulnerable and will put pressure on keeper Asmir Begovic (Stoke City).
FIFA World ranking: 43.
Last World Cup: 2006.
Best World Cup finish: Group stage.
How qualified: AFC Group A winner.
It's a fact: The cash-strapped Iranian soccer federation is so short of uniforms it banned players from participating in the traditional postgame exchange of jerseys with their opponents.
The skinny: Most teams are booked at lush resorts during the World Cup, but Iran's short stay in Brazil will reportedly be at an airport hotel in Sao Paulo's gritty Guarulhos district. But then Iran has had to do everything on a budget in the lead-up to this World Cup, which is why it went 119 days without a game after qualifying for the tournament. Portuguese coach Carlos Queiroz built his team around foreign-based players who qualify for Iranian citizenship, including San Jose's Steven Beitashour (Vancouver Whitecaps), Germany's Ashkan Dejagah (Fulham) and Reza Ghoochannejhad (Charlton Athletic), who grew up in the Netherlands.
FIFA World ranking: 44.
Last World Cup: 2010.
Best World Cup finish: Round of 16 (1994, '98).
How qualified: Beat Ethiopia in CAF playoff.
It's a fact: Nigeria's president briefly banned the national team from international competition after it went winless in its last two World Cup appearances.
The skinny: The reigning African champion, Nigeria warmed up for Brazil with unimpressive draws against Mexico, Scotland and Greece and a loss to the U.S. And though it has qualified for three of the last four World Cups, it hasn't won a game there since 1998. That hasn't hurt the team's confidence, though, with veteran goalkeeper Vincent Enyeama predicting the defense-minded team will become the first African nation to reach the semifinals. Whether that happens will depend on how often playmaking midfielder John Obi Mikel can get the ball to Chelsea teammate Victor Moses or Emmanuel Emenike (Turkey's Fenerbahce) on the counterattack.
— Kevin Baxter