Neymar is the team's talisman and if Brazil are to win a sixth World Cup it is inconceivable they will do so with their best player in such lacklustre form.
Brazil's opening match of the World Cup was supposed to be the game in which Neymar buried the ghosts of 2014 and bounced back from the foot injury that kept him out for most of this year.
Instead, as one of the pre-tournament favourites were held to a 1-1 draw by Switzerland he was a pale shadow of the crowd-pleasing showman widely recognised as the heir to Lionel Messi and Cristiano Ronaldo as the greatest player in the world.
Neymar was carried out of the last World Cup in his homeland on a stretcher after being kneed in the back by Colombian Juan Zuniga in their quarter-final encounter.
The injury meant he missed the 7-1 humiliation by Germany in the semi-finals but it also left him more determined than ever to make his mark on football's biggest stage.
Sunday's Group E game was his first competitive start since February when he fractured a metatarsal and sprained his ankle in Paris St Germain's league match with Olympique de Marseille.
But unlike in the last two Brazil friendlies earlier this month, when he scored goals and inspired his team to victory, he looked out of sorts versus the Swiss and just not up for it.
"Neymar hasn't been bad, but he's been quiet," Brazilian TV analyst and former World Cup striker Walter Casagrande said.
It was not just that the 26-year-old had few chances. It was his reluctance to look for the ball deep in midfield and do what he does best, jink towards goal, teasing and tormenting far bigger defenders and creating chances and winning fouls.
That may be something to do with one of the game's more impressive statistics. Those towering Swiss players took no prisoners, committing 19 fouls to Brazil's 12, 10 of which were on Neymar.
Brazil coach Tite refused to be drawn on whether Switzerland had set out to rough Neymar up but their physical superiority was evident - another standout statistic was that the Swiss covered eight kilometres more ground than the Brazilians.
Tite must hope the malaise that affected his key player – and, it must be said, many of his team mates - will lift before their next game against Costa Rica in St Petersburg on Friday.
Neymar is the team's talisman and if Brazil are to win a sixth World Cup it is inconceivable they will do so with their best player in such lacklustre form.
All bets will be on him producing sooner rather than later, as he has so many times for club and country.
A nation awaits.
