Previewing Groups A through H at the World Cup

The World Cup, the world's most popular sports tournament, begins Friday when host nation South Africa takes on Mexico at 10 a.m. EST.

Thirty-two nations have qualified, led by favorites Brazil and Spain. The Brazilians are trying to extend their record to six World Cup titles, while the Spaniards are going for their first.

Those 32 teams will be divided into eight groups. The two best teams from each group will advance to the Round of 16, where the knockout stages ensue. Here's a look at each group:

GROUP A

France

History: 13th appearance (winner in 1998).

Key players: Revitalized midfielder Franck Ribery, who helped Bayern Munich to the Champions League final, and Chelsea forward Nicolas Anelka.

Coach: Raymond Domenech

Outlook: Few elite teams are as unpredictable. This squad doesn't boast the surpassing skill of a Zinedine Zidane, and top players Thierry Henry, William Gallas are beyond their primes. But Anelka and Ribery can strike at any time, if given freedom to attack by the defense-minded Domenech. Getting beyond the first round could be too large a challenge.

Mexico

History: 14th appearance (quarterfinals in 1970. '86).

Key players: Forwards Giovani dos Santos of Galatasaray and Carlos Vela of Arsenal.

Coach: Javier Aguirre.

Outlook: After struggling for nearly three years since the 2006 World Cup, the Mexicans turned to youthful players such as dos Santos and Vela. Two significant veterans, defender Rafael Marquez and forward Cuauhtemoc Blanco, have lost a step. Still, there's a nice blend for El Tri, particularly with the young attackers and midfielder Andres Guardado showing flair and a finishing touch. Winning this group would be no surprise.

South Africa

History: Third appearance (never advanced).

Key players: Everton midfielder Steven Pienaar and Portsmouth midfielder/defender Aaron Mokoena.

Coach: Carlos Alberto Parreira

Outlook: Every World Cup host has advanced, a streak that is in serious jeopardy this time. Bafana Bafana might be the weakest of the six African nations on hand, although home teams get an immeasurable boost from the environment. A leaky defense and uncertain goalkeeping are problematic.

Uruguay

History: 11th appearance (winner in 1930, '50).

Key players: Atletico Madrid forward Diego Forlan and Ajax forward Luis Suarez.

Coach: Oscar Washington Tabarez

Outlook: Forlan is fantastic, displays a true feel for playmaking and is an elite finisher who led his team to the Europa League championship. If he doesn't get frustrated by defenses designed for neutralizing him, Forlan could be a difference maker for a team that rarely provides much excitement. The defense is spotty and sloppy, but will be physical.

GROUP B

Argentina

History: 20th appearance (winner in 1978, '86).

Key players: World Player of the Year Lionel Messi of Barcelona and fellow forward Carlos Tevez of Manchester City.

Coach: Diego Maradona

Outlook: Where have we heard this before: Argentina will go as far as Maradona takes it. The huge difference is Maradona will be plotting strategy, not dominating defenders on the field. If Messi is magical, as he has been all year for Barcelona, and the defense holds true, Argentina could surge deep into the tournament.

Greece

History: Second appearance (never advanced).

Key players: Olympiakos defender Vassilis Torosidis and Celtic striker Georgios Samaras.

Coach: Otto Rehhagel

Outlook: The Greeks' surpassing soccer moment came when they won the 2004 European Championship in a stunning upset. They are well-coached by Rehhagel, who took them to that title, and put up a defensive wall that would make the classic Italian teams proud. An experienced group, the Greeks must get a spark offensively on one of their infrequent counterattacks. Their marksmanship needs to be precise because they won't get many opportunities.

Nigeria

History: Fourth (reached second round, 1994 and '98).

Key players: Hoffenheim striker Chinedu Obasi, and captain Joseph Yobo, who plays for Everton, on defense.

Coach: Lars Lagerback.

Outlook: Lagerback couldn't get his native Sweden into the tournament and now heads a team with an entirely different skill set. Once considered the power of Africa, Nigeria has struggled in recent years, becoming fragile defensively. It still can attack with Obasi and Obafemi Martins, and it still can get caught out of position all over the field. Low-scoring matches won't suit the Nigerians.

South Korea

History: Eighth appearance (semifinals in 2002).

Key players: Manchester United midfielder Park Ji-sung and midfielder Lee Chung-yong of Bolton.

Coach: Huh Jung-moo.

Outlook: Not the best team South Korea has sent to the World Cup, but the Koreans have veteran leadership, from keeper Lee Woon-jae to halfback Lee Young-pyo to midfielder Park, the captain. If South Korea is to have a breakout player, look for Lee Chung-yong, a burgeoning star in the EPL, to strike.

GROUP C

Algeria

History: Third appearance (never advanced).

Key players: Midfielder Yazid Mansouri, the captain who plays for Lorient, and midfielder Karim Matmour of Moenchengladbach.

Coach: Rabah Saadane

Outlook: As the only Arab nation in the tournament, Algeria carries an extra burden. Its players also carry significant momentum from beating Egypt to get into the tournament, and from a win over the Ivory Coast in the African Cup of Nations. The Algerians need more offense from Rafik Djebbour and Abdelkader Ghezzal.

England

History: 12th appearance (winner in 1966).

Key players: Manchester United striker Wayne Rooney and midfielder Frank Lampard of Chelsea.

Coach: Fabio Capello

Outlook: Injuries are a concern for this veteran squad that is versatile on attack but uncertain in front of the goal - particularly if Chelsea's John Terry goes back into a funk. Netminding has been an issue, too, and England won't survive for long without a steady keeper. Rooney is among the most dangerous attackers in the world, and both Lampard and Steven Gerrard can be brilliant. Unfortunately, they aren't always in top form. A win over the U.S. Saturday should boost England to the group title.

Slovenia

History: Second appearance (never advanced).

Key players: West Bromwich Albion midfielder Robert Koren is the captain, while Udinese's Samir Handanovic will be the keeper.

Coach: Matjaz Kek

Outlook: Their surprising ouster of Russia in a playoff for a World Cup berth made people notice. Strong defensively, with Koren the anchor and Handanovic gaining a reputation as an elite keeper, the Slovenians won't get blown out by anybody.

United States

History: 10th appearance (semifinals in 1930).

Key players: Midfielder Landon Donovan of Los Angeles Galaxy and keeper Tim Howard of Everton.

Coach: Bob Bradley

Outlook: Everything seems set up for the U.S. to advance, but injuries add much uncertainty to their prospects. Few of the top players have remained healthy for long stretches, and the Americans need Clint Dempsey, Oguchi Onyewu, Carlos Bocanegra and several backups to be fit. Donovan never has been better, and Howard is capable of stealing a game.

GROUP D

Australia

History: Third appearance (second round in 2006).

Key players: Goalkeeper Mark Schwarzer of Fulham and midfielder Tim Cahill of Everton.

Coach: Pim Verbeek

Outlook: The Socceroos went out in 2006 on a late penalty against Italy, which went on to win the title. That controversial loss has stewed with fans in the land Down Under. Advancing again will be extremely tough in this group, and Schwarzer will need to be a human wall to make it happen. He's been sensational for Fulham and nothing less will do in South Africa.

Germany

History: 17th appearance (winner in 1954, '74, '90).

Key players: Bayern Munich midfielders Philipp Lahm and Bastian Schweinsteiger.

Coach: Joachim Low

Outlook: The Germans have had a rough two-year patch since losing to Spain in the Euro finals. Last November, goalkeeper Robert Enke committed suicide. His replacement, Rene Adler, is out with a broken rib. Midfielder Simon Rolfes is sidelined with damaged cartilage in his right knee and midfield organizer Michael Ballack is out with an ankle injury. Still, this team is talented, versatile and relentless and figures to be far too physical for these group opponents.

Ghana

History: Second appearance (second round in 2006).

Key players: Chelsea midfielder Michael Essien, who is recovering from a knee injury, and forward Asamoah Gyan of Rennes.

Coach: Milovan Rajevac

Outlook: Ghana was a revelation in the last World Cup, with a beatdown of the Americans propelling it into the second round, where it lost to Brazil. This team's midfield probably is even better, which will help the offense. Essien, if in form, is a difference maker, and could make Gyan and Matthew Amoah more effective.

Serbia

History: First appearance as solo entry.

Key players: Manchester United defender Nemanja Vidic and CSKA Moscow midfielder Milos Krasic.

Coach: Radomir Antic

Outlook: Serbia almost certainly has the best defense in this grouping, led by Vidic, who rarely makes a mistake at center back. Serbia's midfield also is topnotch, and will gather around keeper Vladimir Stojkovic to lighten his load. Key is whether this team can score enough to move on.

GROUP E

Cameroon

History: Fifth appearance (quarterfinals in 1990).

Key players: Inter Milan striker Samuel Eto'o, among the world's best finishers, and Espanyol goalkeeper Carlos Kameni.

Coach: Paul Le Guen

Outlook: The Lions are dangerous, with the brilliant Eto'o capable of carrying them to the top of this group. Cameroon needs steady play in the midfield and to control the tempo and space. Doing so will allow Eto'o to roam in the open field. Of course, Cameroon is known for providing the same kind of open space for opponents to attack.

Denmark

History: Fourth appearance (quarterfinals in 1998).

Key players: Veteran Feyenoord striker Jon Dahl Tomasson, Ajax winger Dennis Rommedahl and Liverpool defender Daniel Agger.

Coach: Morten Olsen

Outlook: A strong qualifying run allowed the Danes to beat out perennial qualifiers Portugal and Spain, but they'll need to find some offense. Tomasson and Soren Larsen will spearhead those efforts. Keeper Thomas Sorensen has to be steady, maybe even spectacular, because Denmark doesn't figure to fill the net often.

Japan

History: Fourth appearance (second round in 2002).

Key players: Former Espanyol midfielder Shunsuke Nakamura, a free kick specialist, and dangerous forward Shinji Okazaki.

Coach: Takeshi Okada

Outlook: The Japanese never have won a World Cup match outside their nation. They surely will need a win in this tournament to have a shot at advancing, and to get it, Nakamura and Okazaki must connect. There's not a lot of creativity with the ball, which means Japan wants low-scoring matches and tight marking.

Netherlands

History: Ninth appearance (runner-up in 1974, '78).

Key players: Winger Arjen Robben and midfielder Wesley Sneijder, who led their teams into the Champions League final, Robben for Bayern Munich, Sneijder for champion Inter Milan.

Coach: Bert van Marwijk

Outlook: A perennial disappointment late in World Cups, the Dutch tend to look dynamic and of championship caliber early on. They should romp in this group behind a deep offense featuring Robben, Robin van Persie, Dirk Kuyt and Sneijder. So the main issue is whether they can stop some of the more powerful opponents down the road.

GROUP F

Italy

History: 17 prior appearances (winner in 1934, '38, '82, '06).

Key players: Goalkeeper Gianluigi Buffon of Juventus and midfielder Andrea Pirlo of AC Milan.

Coach: Marcello Lippi

Outlook: Defending champions with same coach, an aging contingent that should emerge from this group, but might not have the freshness and imagination to get much farther. Lippi will stick with the guys who won him the title, from Buffon in goal to Fabio Cannavaro and Gianluca Zambrotta on defense to Pirlo and Daniele De Rossi in midfield. He does have some new blood up front, and if Alberto Gilardino finds his stride, the Azzurri will have some balance.

New Zealand

History: One prior appearance (did not advance).

Key players: Defender and captain Ryan Nelsen of Blackburn and striker Chris Killen of Middlesbrough.

Coach: Ricki Herbert

Outlook: It's difficult to picture the Kiwis prospering, but the defense is decent and keeper Mark Paston can be masterful. Still, New Zealand will have lots of trouble scoring, and lacks international chops. Don't be surprised if the Kiwis play a lockdown style in hopes of getting a draw or two.

Paraguay

History: Eighth appearance (second round in 1998, '02).

Key players: Manchester City forward Roque Santa Cruz and Borussia Dortmund forward Lucas Barrios.

Coach: Gerardo Martino

Outlook: Injuries have played havoc with the attack, and Paraguay desperately needs a fit Santa Cruz, Barrios and Oscar Cardozo up front. They are the creators, with the midfield and defense playing more traditional roles, although Christian Riveros is capable of sparking the offense. Paraguay allowed only 16 goals in qualifying.

Slovakia

History: First appearance solo.

Key players: Liverpool defender Martin Skrtel and midfielder Marek Hamsik of Napoli.

Coach: Vladimir Weiss

Outlook: Weiss' father, also Vladimir, was a coach. His son, yes, Vladimir is a player, a likely starter in the midfield. Young Hamsik is the captain at all of 22 years old. Everything will be built around him and defensive work of Skrtel and Peter Pekarik. The Slovaks won't put many balls in the net, but if they can outscore Paraguay, advancement is possible.

GROUP G

Brazil

History: 19th appearance (winner in 1958, '62, '70, '94, '02).

Key players: Midfielder Kaka of Real Madrid, the 2007 World Player of the Year, and striker Luis Fabiano of Sevilla.

Coach: Dunga

Outlook: It's never wise to discount the Brazilians. Under Dunga, Brazil will be a more defense-oriented squad, a style that actually suited it well in 1994, with Dunga as captain, and in 2002. Kaka is the orchestrator and a pretty good finisher, too. Luis Fabiano likely will lead the team in scoring, but a half-dozen others, including Robinho and Nilmar, will be dangerous as well. In Lucio and Maicon, the defense is solid, and keeper Julio Cesar steadily has improved and ranks among the world's best.

Ivory Coast

History: Second appearance (never advanced).

Key players: Chelsea forward Didier Drogba and Barcelona midfielder Yaya Toure.

Coach: Sven-Goran Eriksson

Outlook: Probably the best of the six African nations in the field, and certainly one of the most exciting teams thanks to the prolific Drogba, but his availability may be compromised by a broken arm suffered in a friendly. The Elephants will need to stomp on opponents offensively because their defense is suspect.

North Korea

History: Second appearance (quarterfinals in 1966).

Key players: Keeper Ri Myong Guk and FC Rostov striker Hong Yong Jo.

Coach: Kim Jong Hun

Outlook: The mystery team of the tournament and the only country that didn't release its roster in advance. But there is little mystery how it will play: pack it in at the back, venture ahead on counterattacks, and keep the score as low as possible.

Portugal

History: Fifth appearance (semifinals in 1966, '06).

Key players: 2008 World Player of the Year Cristiano Ronaldo, a winger for Real Madrid, and Manchester United midfielder Nani.

Coach: Carlos Queiroz

Outlook: Earlier this decade, the Portuguese were a powerhouse, and their run to the '06 semifinals was impressive. Ever since, they have been a disappointment. They still have some stars, including Ronaldo and midfielder Deco. In previous years, Portugal would be a prime challenger for the group title. Now, it might be hard-pressed to finish second.

GROUP H

Chile

History: Eighth appearance (third in 1962).

Key players: Forwards Huberto Suazo, who previously led Monterrey to the Mexican title, and Alexis Sanchez.

Coach: Marcelo Bielsa

Outlook: Bielsa coached Argentina in 2002, something he'd like to erase from his resume. His native country went out in the first round. Don't expect the Chileans to falter so badly. They can score (32 goals in qualifying) and are pretty deep up front. Suazo is a star in the making, while Sanchez and Mark Gonzalez also are threats. Chile could be a long shot to go far.

Honduras

History: Second appearance (never advanced).

Key players: Tottenham midfielder Wilson Palacios and forward David Suazo of Genoa.

Coach: Reinaldo Rueda

Outlook: They sneaked into the field in the final minutes of qualifying, but advancing from the first round will require a major upset. Another Suazo who can find the net is Honduras' David, and Palacios will engineer the offense along with veteran Amado Guevara. A leaky defense must be patched.

Spain

History: 13th appearance (fourth in 1950).

Key players: Superb midfielders Andres Iniesta of Barcelona and Cesc Fabregas of Arsenal, and Liverpool forward Fernando Torres, who is recovering from right knee surgery.

Coach: Vicente del Bosque

Outlook: The class of the field, which means very little considering the outright favorite rarely wins the Cup. Still, Spain was sensational in winning Euros two years ago and, if it can get healthy, its first world title is within reach. Iniesta, Torres, Xavi Hernandez, David Villa, keeper Iker Casillas and defenders Carles Puyol and Gerard Pique are among the standouts on the deepest squad in the tournament. There will be lots of pressure on them, but this group looks like it can handle it.

Switzerland

History: Ninth appearance (quarterfinals in 1934, '38, '54).

Key players: Forwards Alex Frei, the captain, and Tranquillo Barnetta.

Coach: Ottmar Hitzfeld

Outlook: Frei can be innovative and Barnetta, who is a classic midfielder, rarely is caught where he doesn't belong. Those two must be productive, and keeper Diego Benaglio needs to be stingy, for the Swiss to avoid a quick trip home.