As the atmosphere built before Thursday's curtain-raiser between the hosts and Saudi Arabia, Argentina star Lionel Messi and his teammates and France's talent-studded squad including Antoine Griezmann and Kylian Mbappe were put through their paces.
World champions Germany, seeking to equal Brazil's record of five World Cup wins, will land in Russia on Tuesday, along with Gareth Southgate's youthful England side.
Brazil and Neymar arrived in the Black Sea resort of Sochi in the early hours in buoyant mood after hammering Austria 3-0 in their final warm-up match on Sunday.
Neymar, who broke a bone in his foot in February, marked his first start in more than three months by scoring in Sunday's easy victory in Vienna.
Russia was a disputed choice when it was handed the World Cup in a closely watched 2010 vote that has since been tainted by bribery charges, and the 2018 tournament takes place against a background of international tensions.
Russia and the West have engaged in a major wave of tit-for-tat diplomatic expulsions since London accused Moscow of being behind the poisoning of Sergei Skripal in Britain in March.
But as the clock ticks down to the opener in Moscow's imposing 80,000-capacity Luzhniki stadium, the tournament is beginning to catch the public mood, with about 3,500 fans attending Australia's training session in the central city of Kazan.
Russian supporters, enjoying a holiday, shouted "Aussie, Aussie, Aussie, go, go, go".Socceroos goalkeeper Mat Ryan warned France that a new, improved Australia team are plotting an early World Cup shock when the sides meet in Kazan on Saturday.
"Come the France game, we're going to be ready... and giving ourselves opportunities to win this game," the stopper who plays for Premier League side Brighton warned. "We can't wait for Saturday."
A big question mark hangs over the participation of Egypt and Liverpool striker Mohamed Salah, who is still receiving treatment for the shoulder injury he suffered in the Champions League final.
Team doctor Mohamed Abou al-Ela admitted the striker, who scored 44 goals for Liverpool this season, was unlikely to play in Egypt's opening Group A match against Uruguay on Friday.
But Salah did some light running in Grozny on Monday, monitored by medical staff, as the other Egypt players took part in a group warm-up. Uruguay goalkeeper Fernando Muslera said he hoped Salah would be fit to line up when the two countries clash.
"I like the best players to play, I train with the best and I want the best players to play," Muslera said.
Argentina captain Messi said his international future will be determined by his country's performance at the World Cup.
"It will depend on how far we go, how we're going to finish" at the finals, Messi told Spanish daily Sport.
"We've just lost three finals in a row, which has led to us going through some difficult moments with the press," the Barcelona forward said.
Argentina lost the 2014 World Cup final 1-0 to Germany after extra time, before suffering successive defeats by Chile on penalties at the Copa America in 2015 and 2016.
Even before the tournament gets under way, FIFA has the major task on Wednesday of choosing the host of the 2026 World Cup -- a straight fight between a joint bid featuring the United States, Canada and Mexico and Morocco. A long-awaited report from FIFA inspectors left the North American bid as the front-runner in the race to host the first 48-team World Cup. AFP