Spain hasn't lost any of its 16 games under coach Luis Aragones. He could still be looking for another job within a week.
Spain faces Slovakia on Saturday in the first of a two-leg playoff, with the winner qualifying for next year's World Cup in Germany.
In other European playoffs, the Czech Republic plays at Norway, and 2002 World Cup semifinalist Turkey is at Switzerland. Elsewhere, Uruguay meets Australia, and Trinidad and Tobago plays Bahrain. Five spots remain open for the 32-team field for the June 9-July 9 tournament.
Spain, at home at Atletico Madrid's Vicente Calderon stadium, is under pressure to build a big lead for Wednesday's second leg in Bratislava. Aragones has hinted he won't stay if the team fails to reach the World Cup for the eighth time in a row.
"What's essential is to win. And if it's by two goals, that's better than one. And if it's by three, even better," Aragones said. "I think we're superior in terms of our technical ability and we have to use this to make sure of victory. I think we can win both here and there. I'm sure we'll be in Germany."
Spain, a traditional power, has a poor record in international championships. Its lone title was the 1964 European Championship. Since a fourth-place finish in 1950, it has never been past the World Cup quarterfinals.
Slovakia is trying to get there for the first time since the breakup of Czechoslovakia in 1993.
"We are going to do everything in our power so that everyone who knows nothing about Slovakia will remember us," coach Dusan Galis said. "These games are the most important in our players' careers, and in the careers of those of us who support them."
But Galis is without Marek Mintal, last season's Bundesliga top scorer, and injured midfielder Karol Kisel. Miroslav Karhan and Martin Skrtel are doubtful.
The Czech Republic most likely will field one striker, Milan Baros, in Oslo. Striker Jan Koller is sidelined for eight months after tearing knee ligaments. But Pavel Nedved has come out of international retirement to try and get the team to the World Cup for the first time since 1990.
Brothers Hakan and Murat Yakin, who have Turkish family, are injured and won't be in the Swiss lineup to face Turkey in Bern. Switzerland has beaten Turkey once in their last six meetings.
Trinidad will rely heavily on the experienced tandem of Dwight Yorke and Stern John against Bahrain in Port-of-Spain. Yorke, who played in England for more than a decade and helped Manchester United win the 1999 Champions League title, has returned to international play to help the team get through the qualifying rounds.
John, who plays in England for Derby County, has 64 goals in 89 international games, including two in Trinidad's 2-1 qualifying victory over Mexico.
Two-time champion Uruguay, which last won the World Cup in 1950, plays in Montevideo in a rematch against the Aussies. Four years ago, the Uruguayans won a two-leg playoff to earn a berth at the 2002 World Cup. Australia is looking to return to Germany, where it last played in the World Cup in 1974.
Uruguay striker Diego Forlan is recovering from an injured left leg and is unlikely to be ready for the first game.