The Netherlands, three times finalists, could also qualify from Europe with wins on both Friday and Tuesday while Switzerland and Bosnia could go through if they win and other results go their way.
The United States would seal the first qualifying place from the CONCACAF region with victories in Costa Rica and at home to Mexico while Argentina can guarantee a trip to neighbouring Brazil if they beat Paraguay on Tuesday.
The former world champions, who top the South American standings, could even qualify before they face the bottom-placed Paraguayans if results go their way when they have a rest day on Friday.
With the opening match in Sao Paulo on June 12, just over nine months away, hosts Brazil and the four Asian qualifiers of Japan, Australia, Iran and South Korea are the only countries through so far.
On Friday, the seven nations who will join already-qualified Ivory Coast, Egypt and Algeria in the final African qualifying round will be known.
The 10 teams will be paired up and play each other home and away to decide Africa's five qualifiers for Brazil.
In Asia, Jordan and Uzbekistan, neither of whom have reached the finals before, will meet over two legs on Friday and Tuesday to decide who qualifies for a playoff against the eventual fifth-placed South American team for a World Cup place.
Italy, the European Group B leaders, face second-placed Bulgaria in Sicily knowing that victory, and a win against the Czech Republic on Tuesday, will give them a spot in the finals.
The main talking point in Italy has been who might succeed coach Cesare Prandelli if, as expected, he announces as soon as qualification is secured that he will leave the job after four years at the end of the finals.
The Italian players know what to expect in Brazil after their experience in the Confederations Cup in June when they reached the semi-finals before losing to Spain on penalties.
They will be missing five first-choice players against Bulgaria including the suspended Mario Balotelli, Riccardo Montolivo and Pablo Osvaldo, but the trio will return for the game against the unimpressive Czechs.
Germany are likely to secure their place sooner rather than later, with Group C matches against Austria on Friday and the Faroe Islands on Tuesday.
It would be the Germans' 16th successive appearance in the finals - the last one they missed was when the World Cup was held in Brazil in 1950 following World War Two.
Louis Van Gaal's Netherlands team are the only ones with a perfect record after winning their opening six matches and they are seven points clear of Hungary and eight clear of third-placed Romania.
The Dutch are likely to seal their place in the finals following a trip to Estonia on Friday and a visit to tiny Andorra on Tuesday. Anything other than two wins would be a major surprise.
World champions Spain should keep their grip on Group I, which they lead by one point from France.
Coach Vicente del Bosque is without several key players for Friday's tie against Finland. Finnish coach Mixu Paatelainen has described the game as "a David and Goliath situation", although Finland did hold Spain to a 1-1 draw in Gijon in March.
- Sports & Recreation