EUROPEAN PLAYOFFS (fixtures to be confirmed)
Four-time world champion Italy will be favored to qualify no matter which opponent it faces, yet the Azzurri aren't in top form after a string of discouraging results - a 3-0 loss to Spain, slim 1-0 wins over Israel and Albania, and a 1-1 draw with Macedonia.
However, the expected returns from injury of center forward Andrea Belotti and veteran midfielder Daniele De Rossi could provide a boost. The playoff outcome will likely determine the future of Italy coach Gian Piero Ventura.
Milan's San Siro or Palermo's Renzo Barbera stadium are being considered to host the home leg of the playoff.
Croatia finds itself in familiar territory.
Led by playmaker Luka Modric and other high-profile players in Mario Mandzukic, Ivan Rakitic and Ivan Perisic, the Croatians faced the same hurdle before the 2014 tournament in Brazil, eliminating Iceland 2-0 on aggregate.
In this campaign, Croatia was on course to qualify automatically from the first place before two poor results - a 1-0 loss in Turkey and a 1-1 draw at home to Finland. Those results cost coach Ante Cacic his job.
Under new coach Zlatko Dalic, Croatia won a needed 2-0 victory at Ukraine to seal a playoff spot behind Iceland.
Switzerland was perfect in World Cup qualifying for more than one year: Nine games, nine wins. Now coach Vladimir Petkovic must lift his players after a 2-0 loss in Portugal on Tuesday sent them to the playoffs, where the best runner-up record counts for little except being seeded.
The Swiss have a reputation for being an efficient team in group-stage games that falls just short against good opponents in elimination games. They lost to Argentina at the 2014 World Cup, and Poland at Euro 2016.
Their opponents next month are likely to be below that class, and Petkovic can expect that key forward Breel Embolo - a substitute in Lisbon - will be fully fit after a one-year injury absence.
There's a chance Denmark could face neighbour Sweden, which denied the Danes a spot in the 2016 European Championship by winning their playoff.
Christian Eriksen is the undoubted star of the Denmark team, the playmaker having been one of the best players in the English Premier League over the last two years and scoring eight times from midfield in qualifying.
Denmark was second to Poland in its group, only missing out on automatic qualification in the final round.
Reaching the playoffs came as a relief for Greece's players and coach Michael Skibbe following an embarrassing qualification campaign for Euro 2016, when the team was twice beaten by the Faeroe Islands and finished last in the group.
An stubborn defense was again the key to earning a runner-up spot, nine points behind Belgium, with Skibbe struggling to find stability in midfield and a strike partner for Kostas Mitroglou.
The German coach will look forward to the development of 21-year-old Tassos Donis, who provided some badly needed pace in midfield, as well as the talents of the Portuguese-born Carlos Zeca.
Sweden captain Andreas Granqvist says he'd prefer to not play Italy or Scandinavian archrival Denmark and would rather face Croatia or Switzerland. Sweden, for example, has never beaten Italy in the last 17 years.
Sweden finished behind France in its group, but ahead of the Netherlands, in its first qualifying campaign without retired striker Zlatan Ibrahimovic. Marcus Berg has replaced Ibrahimovic as Sweden's leading striker and scored eight times in the qualifying.
This will be Ireland's ninth time in the playoffs for a major tournament. The Irish have progressed on three occasions, with their most high-profile failure coming against France in the playoffs for the 2010 World Cup when Thierry Henry clearly handled the ball in the build-up to the crucial goal.
In the final round of group play, Ireland beat Wales in Cardiff in a virtual playoff for the playoffs. Coach Martin O'Neill's counterattacking tactics worked perfectly in that 1-0 win and it would be no surprise if he does the same in the playoffs.
After reaching the knockout stage at Euro 2016, the Northern Irish continued their rise in international soccer by finishing runner-up behind Germany in their group. They have never been to back-to-back major tournaments.
There's no chance of a potentially spicy match against neighbouring Ireland, as both are set to be among the non-seeded teams after the seedings are confirmed on Monday.
HONDURAS vs. AUSTRALIA
Both countries have been regulars in recent World Cups, with Honduras looking to make it for a third straight tournament and Australia seeking a fourth in a row.
Los Catrachos - as the Honduras national team is nicknamed - were squeezed out of an automatic place in Russia by Panama, which scored a late winner in a dramatic denouement to qualifying in the CONCACAF region.
Asian Cup champion Australia had its chances to qualify directly, but failed to capitalize on a glut of scoring chances in the last group game against Thailand and ended up finishing in third spot behind Japan and Saudi Arabia.
The Socceroos then beat Syria 2-1 after extra time to clinch the two-legged Asian playoff, but only after Syria hit the post with a free kick in the last moments of the second leg.
The Australians were most recently in an inter-confederation playoff in 2006, when they ousted Uruguay over two legs.
PERU vs. NEW ZEALAND
In New Zealand's favour is a more recent appearance at the World Cup - going through the group stage in 2010 unbeaten but still being eliminated - and a first taste of Russia by qualifying for the Confederations Cup in June.
But more than a 100 places separate New Zealand and Peru in the FIFA rankings. While New Zealand is at No. 113, Peru has surged to 12th as it chases a first visit to the World Cup since 1982.
Peru claimed fifth place in the tough South American qualifying group to set up the intercontinental play-off that will be played over two legs on Nov. 6 and 14.