Brazil head coach Tite has admitted that Neymar is "not 100 percent" ahead of the Selecao's World Cup opener against Switzerland in Rostov on Sunday.
The Paris Saint-Germain forward has been out of action since February with a broken metatarsal in his right foot, missing the final few months of the domestic season and only returning for Brazil in two friendlies against Croatia and Austria.
Neymar will almost certainly still start the game, but it remains to be seen whether he will be able to finish, or at what sort of level he will be able to play. Tite, though, was optimistic that his star man would have an impact on the game, despite his preparation.
"Neymar is not 100 percent yet," Tite said. "But he is privileged and strong physically -- he is very quick, and he hasn't lost that. I hope he'll be ready, but the medical staff knows better. He's good enough to play very well."
World Cup 2018 must-reads
- Make your picks with ESPN FC Match Predictor 2018!
- Welcome to the Alternative 2018 World Cup Fans' Guide
- ESPN FC's experts make their picks
- Marvel's amazing World Cup spoilers
- Revealed: World Cup 2018 Ultimate XI
- Fixtures, results and full coverage
- Team-by-team previews of all 32 nations
Tite confirmed that his whole squad was fit to play, other than new Manchester United midfielder Fred, who is still recovering from an ankle injury.
It seems likely that Chelsea's Willian will start in attack alongside Neymar and Gabriel Jesus, with Philippe Coutinho playing a slightly deeper role.
The Brazil team's fortunes have transformed under Tite, under whom they have only lost once in 21 games and were the first team to qualify for the World Cup, after hosts Russia.
That prompted the suggestions from the media that he is the only person in the country who is "universally liked," but while Tite disagreed with that, he was undoubtedly happy with the progress his team has made.
"I am not universally liked," the former Corinthians manager said. "I am respected, but a lot of people don't like my style, or me as a person. Some people we have conflicts [with], but what we have as a group is different characteristics, but we have respect, which is very good.
"The work we've done so far not only gives expectations but also a lot of inner peace. We've done a lot of preparation, which has been building up for a long time. We expect a very similar performance to what we had in the qualifiers."
Brazil, of course, will be looking to erase the memory of their humiliation in the 2014 World Cup on home soil when Germany beat them 7-1 in the semifinal. However, team captain Marcelo doesn't believe that game will have an impact on the team.
"These are things that happen in football," the Real Madrid left-back said, when asked if he has yet got over the "trauma" of that night. "Of course I wish it were different, but there is no trauma. If there was a trauma, I wouldn't be playing football anymore. I would have retired.
"I like to have new challenges -- tomorrow is another challenge, not to get hurt, to change from the national team to my club. I don't have any trauma: I don't let the good things get to my head and I don't let the bad things get me down either."