Brazil are monitoring the fitness of forward Antony after the Manchester United man reportedly missed training through illness on Friday.
Tite's side have already lost Neymar and Danilo through injury after their first game of the World Cup, but the favourites are now sweating they will be another man short for their game against Switzerland on Monday.
According to The Sun, Antony was one of several players to miss training alongside Lucas Paqueta and Alisson.
It's unclear at this stage how serious the illness is, but Tite will be hoping he will be able to call on the 22-year old on Monday.
He was a second half substitute in their 2-0 win over Serbia on Thursday, playing 10 minutes after being introduced for Neymar.
The forward had missed United's last few games before the Premier League paused for the tournament, but it is not thought the issues are related.
Meanwhile, Brazil have refused to rule Neymar out of the World Cup, but he is not expected to play again until the knock-out rounds after twisting his ankle in the Serbia match.
Real Madrid striker Rodrygo is most likely to replace him against Switzerland on Monday, and Tite will not risk his playmaker in the third group game against Cameroon if he thinks Brazil can progress without him.
Tite could also call on Arsenal's Gabriel Martinelli or his Gunners team-mate Gabriel Jesus to replace Neymar, while Flamengo's Pedro is also an option.
Right back Danilo, who also suffered an ankle injury against Serbia, will not play any part in the two remaining group games either, and his absence could mean a World Cup return for Dani Alves at the age of 39.
Brazil will be confident of comfortably making the knock-out stages despite Neymar's absence after their comfortable victory on Thursday in arguably their most difficult fixture of the group stages.