Hamburg - Cristiano Ronaldo is absent for Portugal while France must cope without the injured Franck Ribery as two of the pre-qualifying favourites go into the play-offs for a place at next year's World Cup finals. Although Portugal and France may still be counted as favourites, all the European play-offs over two legs on Saturday and Wednesday look close.
Portugal take on Bosnia-Herzegovina in Lisbon, France travel to Dublin to meet Ireland, Russia greet Slovenia in Moscow, while Greece and Ukraine meet in Athens in Saturday's first-leg games.
In the remaining berths for South Africa, New Zealand play Bahrain in Wellington, while on Sunday Costa Rica take on Uruguay in San Jose.
World footballer of the year Cristiano Ronaldo has been ruled out with an ankle injury for both Portugal's play-off matches against a Bosnia side capable of causing an upset.
"It's really frustrating not to be able to help Portugal, particularly at such a key moment like the play-off against Bosnia," the Real Madrid striker said.
"I'll go to the stadium to support my team-mates. I'm sure that the quality of our football will surmount everything and afterwards I'll be in the locker room to celebrate the first of two steps towards the World Cup."
Bosnia, who finished second behind European champions Spain in their qualifying group, regard themselves as outsiders despite Portugal's struggle even to finish second behind Denmark in their group.
"They have a great team and a huge amount of experience, although that doesn't mean we don't stand a chance. There are two games, and we'll give it everything," Bosnia striker Edin Dzeko said.
"If we can come away from their place with a decent result, anything's possible."
France will also be hoping to put a stuttering qualifying campaign behind them when they come up against Giovanni Trapattoni's Ireland side in Dublin.
France coach Raymond Domenech, who remains under fire, said: "There are matches which don't need external pressure. It's here - the players want to go to the World Cup. They are ready."
Greece, under Otto Rehhagel, have to overcome Ukraine if they want to qualify for their first World Cup finals following three failed attempts.
"Of course they are going to be difficult opponents - it won't be an easy match," Greece striker Theofanis Gekas told FIFA's website.
"Still, I think we have a good chance, and we control our own destiny. If we perform to the best of our abilities then I'm sure we'll be on the plane to South Africa."
Russia, under Dutch coach Guus Hiddink, went into the play-offs after finishing behind Germany and are favourites to overcome Slovenia, but question marks remain over the Russians' ability to turn possession and flair around the box into goals.
Slovenia, who narrowly missed pipping Slovakia at the top of their group but left the Czech Republic and Poland behind them, are ready to spring another surprise.
Costa Rica have recovered from the agony of just missing out on direct qualification and are ready for Uruguay in the first-leg play-off in San Jose.
Los Ticos conceded a late goal against the United States in their final game of the North, Central America and Caribbean zone qualifying, while Uruguay were edged out of an automatic place by Argentina in the South American round.
New Zealand and Bahrain do battle in the Oceania/Asia play-off in Wellington after their first leg finished goalless in Manama last month. The All Whites are aiming to return to a World Cup finals for the first time since their debut in Spain in 1982, while Bahrain are hoping to reach the finals for the first time.
