Your handy World Cup guide

BOSTON — In the soccer world, this is a time of cheers and tears, as the round-robin phase of World Cup qualifying comes to an end in both of the game’s most powerful empires, Europe and South America, as well as in America’s CONCACAF region.

After these concluding games — Saturday and Wednesday — 21 teams, or more than two-thirds of the 32-team field will have qualified for the next June’s World Cup Final in South Africa.

The U.S. team, despite its current lofty rating — 11th in the world — and its occasional stunning upset — 2-0 over then-world number one Spain in the recent Confederations Cup — is not held in quite the same regard as the elite European and South American powers.

Still, the U.S. team has become one of the World Cup perennials (or more accurately a quadrennial) ever since it qualified for the 1990 Cup after a 40-year absence from the competition. It is one of only seven nations — Brazil, Argentina, Germany, Italy, Spain and South Korea are the others — to play in every World Cup since 1990.

Brazil, Spain and South Korea have already qualified for 2010 while Italy only needs a draw with Ireland or a victory over Cyprus to be assured of a spot in South Africa. But the other three nations find themselves in surprisingly precarious positions with their Cup streaks potentially in jeopardy.

Both Germany and Argentina are assured a number one seed if they reach South Africa, and either nation’s absence from the fray would be, arguably, the most stunning failure of the modern World Cup era. A U.S. flop would hardly measure up to that. But it would still be a revenue blow to Cup organizers who would prefer that American and Chinese fans have a rooting and, thus, viewing interest in every World Cup. (China already went out in an early qualification round.)

Here’s a look at the teams at the center of the unfolding drama:

Germany/Europe:

Four years ago Germany hosted the World Cup yet, despite its soccer pedigree, expectations were modest for the young, inexperienced team. German fans appeared genuinely delighted when Jurgen Klinsmann guided the home team to a third-place finish. Now Germany fields a formidable, veteran team, which went to the finals of Euro 2008 before losing to Spain 1-0, and is regarded as a serious contender for the World Cup title.

Germany’s qualification problem doesn’t stem from poor play — it has outscored opponents 22-4 through eight games, and a tie with Finland is the sole blemish on its record — but from the luck of the draw. Only the group winner is assured a World Cup spot. And Germany got stuck in a group with Russia, which has continued the strong play that saw it to the Euros semi-finals, where it too lost to Spain.

Russia’s only misstep was a 2-1 loss to Germany in Munich. But a victory in the rematch Saturday in Moscow would put Russia atop the group, requiring only a clinching victory Wednesday over winless Azerbaijan. That would relegate Germany to a head-to-head, two-match playoff with one of seven other group runner-ups battling for Europe’s four remaining spots in South Africa. While Germany would be favored, there is plenty of worry in a random draw that could pit it against any of five teams — France, Croatia, Greece, Portugal, Czech Republic — ranked in the world Top 20.

Germany has won more World Cup games than any nation but Brazil and its absence — almost unimaginable — from South Africa would add considerable sturm und drang to the already volatile political landscape at home.