100 days to the World Cup: Favourites, stars, Mexico's big hope

EXCLUSIVE: Infantino hopeful 2018 & 2022 World Cups change perception of hosts (1:43)

FIFA president Gianni Infantino tells Gab Marcotti about his hopes that the 2018 and 2022 World Cups change negative perceptions of Russia and Qatar. (1:43)

Tuesday marks 100 days until the 21st edition of the FIFA World Cup begins, with hosts Russia facing Saudi Arabia in Moscow on June 14.

Who are the favorites?

This should not come as a surprise but defending champions Germany are the favorites to win it all, according to Westgate Las Vegas Superbook, coming in at 4-1. Germany could become the third team to win consecutive World Cups, joining Italy (1934 and 1938) and Brazil (1958 and 1962).

Germany will hope to break a recent trend of the defending champions going home before the knockout round; three of the last four defending champions failed to make it out of their group.

FiveThirtyEight's Soccer Power Index sees things slightly differently and gives Brazil a 21 percent to triumph (this does not factor in Neymar's injury).

What is at stake for the tournament's biggest stars?

Lionel Messi has won nearly everything in his career, including La Liga and Champions League titles, as well as five Ballon d'Or trophies, but he is still seeking his first international title at the senior level. Although he had a strong performance in Brazil four years ago as Argentina lost in the final, he has struggled historically on the World Cup stage, scoring five goals and recording three assists in 15 career games.

Argentina struggled during qualifying and were in danger of missing qualification on the final day before Messi responded with a hat trick against Ecuador to rescue the team's World Cup hopes and secure a third-place finish in CONMEBOL.

Cristiano Ronaldo finally reached the pinnacle on the international stage when Portugal won Euro 2016. It was the country's first major international title and their captain was named to the team of the tournament, winning the silver boot with three goals and three assists.

But, at 33, this might be his last World Cup. He scored 15 goals in qualifying but has just three goals and two assists in 13 games at the finals. In 2014, Portugal were eliminated in the group stage as Ronaldo struggled with thigh and knee injuries.

Neymar has thrived since his €222 million move from Barcelona to Paris Saint-Germain last summer. His 13 goals and 19 assists in the league means that, in Europe's top five leagues, only he and Messi have reached double digits in both categories.

However, with a foot injury that might keep him out until May, Neymar may only have a matter of weeks to get back to match fitness before Brazil meet Switzerland on June 17. This could lead to a familiar refrain for Brazil: Each of its last three major-tournament eliminations occurred without their star forward on the field.

Can Mexico carry CONCACAF?

This will be a seventh straight World Cup appearance -- 16th overall -- for El Tri, which is the most World Cup berths of any team not to have won the tournament. Mexico is drawn with Germany, Sweden and South Korea in what is the second-toughest group in Russia, according to the SPI, which gives Juan Carlos Osorio's men a 51 percent chance to reach the knockout round.

Mexico has advanced out of its group at six straight World Cups, the third-longest active streak behind Germany (16) and Brazil (12). However, that's where the story ends each time. Mexico seeks its first knockout-stage win away from home soil.