Lionel Messi knows the teams he fears most at the 2018 World Cup: champions Germany, Brazil, France and Spain.

"I think that at the moment, they're the strongest teams who look the best, are playing the best, with the best individuals," Messi told TyC Sports, an Argentine TV channel, last week.

The five-time Ballon d'Or winner identified the key criteria that will spearhead their challenges: strong squads, star players, a team identity and looking the part.

But while naming the would-be contenders isn't hard, what is in store for the rest of the 32-team field?

- The Usual Suspects -

The five giants have won 13 of the last 16 World Cups between them. Spain and Germany both qualified without losing, while Brazil sealed first place in the South American group with four rounds to play.

France won their group but, as in the Euros last year, were alternately brilliant and toothless, such as in a shocking 0-0 draw at home to Luxembourg.

Argentina squeaked through by winning their last game, away to Ecuador, and inevitably it was Messi who hit a hat-trick to save his nation when staring into the abyss of elimination. How Italy wish they had a Messi in their ranks. But that near miss hardly bodes well for a country dreaming of emulating the Diego Maradona inspired victory of 1986.

Yet form can be misleading, as Spain and Brazil's crushing losses to the Dutch and Germans four years ago showed.

- Sleeping Giants -

England won in 1966, but since then the nation that invented the sport and boasts the richest league in the world, has reached just one semi-final. Gareth Southgate, the England manager, has been blooding youngsters from the successful youth teams and there is reason for optimism in England, but maybe 2018 will come too soon.

According to FIFA, Mexico has the third highest number of registered footballers -- behind only Brazil and Germany -- amongst World Cup finalists, yet in 15 finals appearances, they have never gone past the quarters.

With 142 million people, Russia have the biggest population of any of the finalists. The Soviet Union once reached a semi-final, but that was a long time ago and in a different world. Recent scandals surrounding Russian sport mean that success for the hosts might be greeted with more suspicion than acclaim.

- Small Nations with Big Hopes -

With a population of just over three million and two World Cup titles, Uruguay are again following their own succesful template. They have produced enough top-end talent, led by Luis Suarez, Diego Godin and Edinson Cavani, to give them a chance of beating anyone.

Croatia have Luka Modric, Ivan Rakitic and Ivan Perisic, which is good, but they finished second to Iceland in their qualifying group, which is not.

Portugal have Cristiano Ronaldo, but their greatest success -- winning the 2016 Euros -- came despite playing without the world player of the year for three-quarters of the final.

Belgium are enjoying a golden generation, but Switzerland and Denmark have only silver and bronze ones.

Poland, not such a small nation in population terms, have the prolific Robert Lewandowski, the top scorer in global qualifying with 16 goals.

- Underdogs with sharp teeth -

In 2002, as joint hosts, Japan and South Korea ran deep into the knockout rounds. This time, along with Australia, they lack world-class talent but bring a work ethic that makes them teams to avoid.

Colombia, Senegal and Nigeria bring skill, pace and power and a bad habit of agonising exits caused by careless errors or bad luck.

Serbia and Morocco both qualified impressively but lack the star man who can make a difference. Iceland will strive to continue to defy gravity.

- Happy to be back -

Peru, once regulars, had not qualified since 1982 until they beat New Zealand on Thursday. They prepare for Russia ranked an unlikely 10th in the world.

Dour Sweden, former finalists, smothered Italy in a play-off but if the smell of glory draws Zlatan Ibrahimovic out of retirement, a blunt instrument would acquire a sharp edge.

Egypt have won more African titles than any other nation but their World Cup record is miserable, and this is only their third appearance.

- Those that make a draw kind -

Costa Rica reached the last eight in 2014 and are ranked 22nd but alongside Iran and Tunisia will still be the teams in the third pot everyone wants to draw.

Tunisia and Saudi Arabia both won games in the first of their four finals appearances but neither has won since and their last points came when they drew 2-2 in Stuttgart in 2006.

Panama may already have used up their miracle, scoring two minutes from the end of their qualifying campaign to beat Costa Rica, eliminate the United States and qualify for their first finals.