A draw will guarantee Brazil a place in the first round of the knockout stages, where they will face either Holland or Chile, while a win will likely see Luiz Felipe Scolari's side go through on top.
Mexico could still progress as group winners if they beat Croatia and either better Brazil's goal difference, which is currently superior by one, or match the hosts' goal difference and triumph on goals scored, where they currently trail Brazil by two.
Mathematical permutations aside, Brazil should have no problems against Cameroon, who are yet to register either a point or a goal in the tournament. But the match is more than just about victory or qualification. Scolari's side need to find a fluidity, creativity and rhythm that has been so lacking in their opening two displays against Croatia and Mexico and so prevalent during the tournament overall so far.
Of Brazil's attacking stars, only Neymar has come close to fulfilling his potential, while Fred, Hulk, Willian and Paulinho have all disappointed. Fred's displays have been particularly underwhelming and he may make way for Jo, who looked livelier when he came on as a substitute against Mexico.
Whoever starts as centre forward, Brazil will need more movement, pace and fluency if they are to convince supporters they are capable of living up to their billing as tournament favourites.
Bernard told FIFA's official website this week: "During a game, Felipao [Scolari] is able to see situations where we might catch our opponents out.
"He might ask us to switch positions for a bit, to try and create more openings. And it works too: it was from the left that I supplied the ball that nearly brought a headed goal from Thiago Silva [against Croatia] when their keeper made a fantastic save."