Brazil still haven't sealed their progression to the round of 16 and face a Serbian team in Moscow capable of an upset.
Like many of the other strong teams in the tournament, the famous green and yellow have failed to impress in Russia - drawing 1-1 with Switzerland before defeating Costa Rica 2-0 with two injury time goals.
If they lose to Serbia and the Swiss draw or win against Costa Rica, it will be an early exit for the Brazilians - who many ranked as tournament favourites.
Philippe Coutinho has been their star player so far, scoring the opening goal against Switzerland and the go-ahead strike against Costa Rica - making it three goals in three Brazil apperances for the Barcelona attacker.
Neymar has looked dangerous but has been tightly marked by opponents so far in the tournament. He has been directly involved in 18 goals in Brazil's last 17 matches and still has another gear to go to in Russia.
The Serbians aren't to be taken lightly and will be led up top with Newcastle United striker Aleksandar Mitrovic - who has scored 18 goals for club and country in 2018.
There is quality players spread throughout the starting line-up including Lazio talent Sergej Milinkovic-Savic, Manchester United's Nemanja Matic and former Premier League stars Branislav Ivanovic and Aleksandar Kolarov.
As an independent nation split from Yugoslavia, Serbia have lost all six World Cup matches they have conceded a goal in but have won the two they have kept a clean sheet in.
They have faced Brazil 19 times (including as Yugoslavia) in all competitions, only winning twice, drawing seven and losing 10.