Five-times world champions Brazil could be without midfielder Lucas Paqueta for their next World Cup Group G game against Switzerland on Monday.
Brazil were already set to miss their talisman Neymar and reliable full back Danilo, both ruled out by ankle injuries suffered in their opening 2-0 win over Serbia.
The World Cup favourites trained behind closed doors at the Al Arabi Stadium on Saturday and coach Tite gave no clue about team selection in his news conference on Sunday.
But Reuters has learned that Paqueta was unable to train fully, affecting Tite's plans to compensate for Neymar's absence against the Swiss.
Real Madrid prodigy Rodrygo would be the first option if Tite decides to use the same system with four up-front alongside Vinicius, Richarlison and Raphinha.
The versatile 21-year-old forward played in Neymar's position in three practice games in Turin before the World Cup.
But the option of pairing Fred with his Manchester United team mate Casemiro to strengthen the midfield is also very much in play, pushing Paqueta forward into a playmaking role if he recovers in time.
Real Madrid's versatile centre back Eder Militao is likely to replace Danilo.
The 24-year-old played as a full back in their friendly against Ghana in September and would add the solidity needed to balance the ultra-offensive tactics Tite is deploying.
Another option would be 39-year-old veteran Dani Alves, the only right back available in the squad.
"I have already made my decision but will not disclose until game time," Tite said.
"In strategic terms, I can make my decision regarding some behavioural changes or changes in the characteristics of players I have available.
"Militao has already played in that role, he has the characteristics to do so. Dani (Alves) is a constructor, apart from his technical and leadership quality. We will see..."
Tite is optimistic about Neymar's recovery from his injury and that he will have his talisman back in time to help them win a record-extending sixth World Cup title.
"I believe that Neymar and Danilo will play again in the World Cup," said on Sunday.
"Medically, clinically, I have no place to speak. But I do have our doctor's opinion, the sensations talking to the players and seeing how hard they are working day and night to recover.
"I believe we will be able to count on them in the World Cup again."