Brazil must do without injured star forward Neymar against Switzerland at the World Cup on Monday as Cristiano Ronaldo looks to lead Portugal into the last 16 in Qatar.
Five-time world champions Brazil can secure a spot in the knockout phase with a win over the Swiss, who held Tite's side to a 1-1 draw in the 2018 group stage.
Brazil kicked off their campaign in Qatar with a 2-0 victory over Serbia in Group G but Neymar limped off with a sprained ankle.
"At the time it was difficult for him and after the game he was sad which I think is normal given how much he has dreamt of this," said Brazil centre-back Marquinhos.
"Now, after the tests and the treatment, he is doing physiotherapy 24 hours a day which shows how much he wants to be back with us.
"We don't know when, but we hope it's as soon as possible."
Switzerland centre-back Nico Elvedi said side would not be awed by the might of Brazil, insisting they had enough quality to push the tournament favourites.
"Every team in this world is beatable," said the Borussia Moenchengladbach defender.
"We know the challenge, but we are not going to hide away. We know our quality and what we are able to show."
Ronaldo became the first man to score in five World Cups after converting a disputed penalty in Portugal's opening 3-2 victory over Ghana in Group H.
The Portuguese will qualify for the second round if they beat Uruguay at the Lusail Stadium, which will host the final on December 18.
Danilo Pereira has been ruled out of the rest of the group stage after fracturing three ribs in training, meaning 39-year-old Pepe is likely to start in defence.
It would make him the second oldest outfield player ever to appear in a World Cup match, after Cameroon great Roger Milla.
- Cameroon still in the hunt -
Cameroon kept their hopes of making the last 16 of the alive after fighting back from two goals down to draw a thrilling encounter with Serbia 3-3.
Rigobert Song's team looked almost dead and buried after goals from Strahinja Pavlovic, Sergej Milinkovic-Savic and Aleksandar Mitrovic gave Serbia a 3-1 lead early in the second half.
But substitute Vincent Aboubakar and Eric Maxim Choupo-Moting snatched a draw with two quick-fire strikes just after the hour to leave both Cameroon and Serbia on a single point, two behind group leaders Brazil and Switzerland.
Had they lost, Cameroon would have been relying on the Swiss beating Brazil in order to not be eliminated with a game to spare, but instead the west Africans still have a chance of getting out of the group stage for the first time since 1990.
Rigobert Song's side must beat Brazil in their final game to have a chance of progressing.
"We believe we can do it against Brazil," said Song.
"We didn't come to the World Cup to just make up the numbers, to take part. We think we can still have a say in the tournament even if we know Brazil are a great team."
South Korea coach Paulo Bento says the team will see a "different" Son Heung-min against Ghana after the forward got used to his protective face mask during their 0-0 draw with Uruguay.
Before coming to Qatar, Son had surgery to repair a fracture around his left eye he suffered while playing for Tottenham Hotspur earlier this month.