Moscow: Neymar's acclaimed return ahead of the World Cup supplied Brazil with an immeasurable boost, but holders Germany and Argentina arrive at the tournament battling inconsistent form and disrupted preparations.
The Paris Saint-Germain superstar's swashbuckling display in a 45-minute appearance against Croatia last weekend largely dismissed lingering concerns over his fitness after more than three months out with a fractured foot.
The 26-year-old admitted he was only at "80 percent" but promised he would be raring to go come Brazil's first game at the finals against Switzerland on 17 June.
"For the first match back I actually expected less from him! I would have been happy with a quieter performance," Brazil coach Tite said of Neymar's eye-catching performance. "What he did was really extraordinary."
Brazil's form under Tite, appointed coach midway through a faltering qualifying campaign, suggests it will be difficult to stop the five-time world champions from adding another title in Russia.
A reinvigorated Selecao have won 16 of 20 matches with the former Corinthians boss at the helm, a 1-0 loss to Argentina last year in Melbourne the only defeat since he took charge.
Spain, unbeaten since Julen Lopetegui was appointed coach after Euro 2016, are back among the genuine contenders after a catastrophic 2014 World Cup and another early exit the European Championship.
"Spanish football has lived through an extraordinary, historic period in 2008, 2010 and 2012, but after that the team has not found the same consistency or success," Lopetegui told AFP.
"We have to grow again as a team. We have the biggest ambitions but we are also very aware that we arrive at this World Cup feeling humble and wanting to prove ourselves."
Spain cruised through a qualifying section featuring Italy, and delivered a further warning to their World Cup rivals with a 6-1 demolition of Argentina in March.
But they will be tested immediately in Russia when they launch their group stage campaign against Cristiano Ronaldo's Portugal on June 15 in Sochi.
Concern for Germany
Germany received a timely shot in the arm with the return of goalkeeper and captain Manuel Neuer after eight months out with a foot injury.
But Joachim Loew's side are struggling for form ahead of their title defence following a run of five matches without a win, and a first defeat to neighbours Austria since 1986.
"If we play like that in Russia, then we have no chance," Loew raged after Germany lost 2-1 to Austria in Klagenfurt last Saturday.
The Germans will be without Mesut Ozil for their final warm-up match against Saudi Arabia due to injury, although centre-back Jerome Boateng could play his first game since April following a groin problem.
Argentina's build-up was jolted by the cancellation of a controversial friendly against Israel in Jerusalem, a fixture set to be their final outing ahead of the World Cup.
The sold-out game had been due to take place on Saturday but was hotly opposed by Palestinians, who claim the eastern part of the city, annexed by Israel, as the capital of their future state.
"Argentina is seven days from the World Cup. We want to focus on what is really important and which is before us," an Argentine football federation spokesman told AFP.
Lionel Messi scored a hat-trick in a 4-0 rout of Haiti last month, but the friendly against a nation ranked 104th in the world was hardly a rigorous examination of Argentina's credentials.
Pogba worry for France?
A hugely talented France squad head to Russia with high expectations, but Didier Deschamps is still struggling to find a system that will enable him to unlock the full potential in his team.
Paul Pogba, who will have a huge role to play if France are to succeed, was jeered by a smattering of home fans after an underwhelming performance in a recent 3-1 win over Italy.
"The whistles are part of football, you have to stay tough mentally. We're all playing for the same shirt," said Antoine Griezmann, in defence of the Manchester United midfielder.
"He plays his game, you're used to him scoring. We don't expect that from him, only that he rotates the ball and plays for the team."
Unburdened by modest expectations, England's youthful side will go into the tournament riding a 10-match unbeaten run that stretches back nearly a year.
Gareth Southgate admitted he faces a selection dilemma after Marcus Rashford starred in a 2-0 win over Costa Rica, but a reasonable draw could allow them to reach a first World Cup quarter-final since 2006.
Updated Date: Jun 12, 2018 16:38 PM