The first team to qualify for this year's World Cup, Brazil's campaign was transformed by the appointment of Tite in June 2016 after a rocky start under his predecessor Dunga. A subsequent run of eight straight wins ensured the five-time champions preserved their proud record as the World Cup's only ever-present nation and revived hopes of landing another title. Their plans were nearly torpedoed when Neymar fractured a bone in his foot in February, but the 26-year-old is back training with the national team ahead of a redemption mission following their 2014 semi-final humilation on home soil.
With Brazil clear group favourites, Switzerland and Serbia figure to battle it out for second place although Costa Rica will be quietly confident too after reaching the quarter-finals four years ago.
The Swiss, who threatened to force Portugal down the play-off route in qualifying, beat eventual champions Spain at the 2010 edition and took Argentina to extra time in the last 16 in Brazil but have yet to properly exceed expectations on the big stage.
Serbia return to the World Cup after missing out on the last tournament but coach Mladen Krstajic will be taking charge of his first competitive match in Russia having replaced Slavoljub Muslin following qualification.
Costa Rica were steady, if not spectacular as they sealed a place at a fourth finals in five tries.
Real Madrid goalkeeper Keylor Navas is his country's most high-profile player and conceded just twice in five matches before an agonising penalty shootout lost denied Costa Rica a spot in the last four at the 2014 World Cup.