Costa Rica suffered defeat to Serbia in their opening fixture, but victory in St Petersburg will give Oscar Ramirez's team every chance of qualifying for the last 16 as well as putting Brazil on the brink of elimination.
Brazil went into this tournament holding an 11-match-unbeaten streak, and that was extended to 12 matches with a 1-1 draw against Switzerland on Sunday evening.
However, the stalemate with the Swiss has threatened to undo all of the hard work of the past four years, with Brazil now needing to win both of their remaining fixtures in order to guarantee progression into the knockout stages.
There were positives to take from their opening fixture - Brazil created 21 opportunities and had the majority of possession - but their display lacked the fluency that you would expect from Tite's side, and Brazil can now not afford to underperform against Costa Rica.
The treatment of Neymar became a talking point with the most expensive player in the world being fouled on 10 occasions, but that comes with the territory and Valon Behrami playing close attention to the Paris Saint-Germain player will only encourage Costa Rica to do the same.
Doubts remain over the fitness of Neymar, but Brazil are still blessed with talent all over the pitch and a below-par outing from their star man should not detract from the fact that just five shots were registered on target.
The statistic was highlighted by Tite in his post-match press conference, and it suggested that the 57-year-old is not afraid to make instant changes to his starting lineup at a time when two positives results are essential.
Brazil will not panic just yet - they have a strong head-to-head record against Friday's opponents and depending on the result between Serbia and Switzerland, they could potentially face Serbia with the European nation having already earned a spot in the second round.
That said, Brazil are now in a position where they cannot take their foot off the gas, regardless of the permutations. A nation expects more four years on after the embarrassment of losing 7-1 to Germany on their home turf and being held by Switzerland would not have been warmly greeted back in South America.
Recent form: DWWWWD
Despite their exploits four years ago when a last-eight appearance was achieved, Costa Rica went into this tournament as the outsiders to qualify from Group E and Ramirez's side are going to have to do it the hard way if they are to make the last 16.
While it took a moment of brilliance from Aleksandr Kolarov to earn victory for Serbia last weekend, Costa Rica were second best for the majority of the game and were fortunate to only lose by a one-goal margin.
The Central American nation saw more of the ball against solid opponents but for the most part, they were ineffective and will take little confidence into a clash with a team possessing the ability of Brazil.
Much has been made of the age of the squad - which is the second oldest in the tournament - and it is difficult to disagree that Costa Rica may struggle to get a point on the board in this group.
Ramirez has stressed to his team that they can still be competitive in this competition, but Costa Rica have now lost seven of their last nine matches, with their victories coming against Scotland and Northern Ireland.
Facing Brazil in a must-win match means that finding a balance will be difficult, but Ramirez could decide to bring Joel Campbell back into the team in a bid to liven things up in the final third.
Campbell has spent the majority of his club career being deemed surplus to requirements at Arsenal and spending time on loan at a number of different clubs, but the 25-year-old remains the future of his team and Ramirez may feel the need to show faith in the attacker.
Whether Campbell is capable of adding to his 15 international goals remains to be seen, but the team needs an injection of pace and trickery and Campbell could be the man to provide that.
Recent form: WLWLLL
As of Wednesday, Neymar had missed two training sessions ahead of his team's next match and Tite must decide whether to take a risk on the frontman.
Campbell is in contention to start for Costa Rica in the final third, with Johan Venegas potentially having to settle for a spot on the bench.
The remainder of the team could remain the same, depending on how those who started Sunday's encounter have recovered this week.
Brazil possible starting lineup:
Alisson; Danilo, Thiago Silva, Miranda, Marcelo; Fernandinho, Casemiro; Coutinho, Willian, Neymar; Firmino
Costa Rica possible starting lineup:
Navas; Gamboa, Gonzalez, Acosta, Duarte, Calvo; Campbell, Guzman, Borges, Ruiz; Urena
Head To Head
Friday's meeting will be the 11th match between the two nations, with Brazil registering nine victories and Costa Rica prevailing on just one occasion.
That triumph came all the way back in 1960, and it means that Brazil have put together an eight-match winning streak in this fixture.
The teams have only met twice since 2004, with Brazil winning friendlies by a 1-0 scoreline in 2011 and 2015.
We say: Brazil 3-0 Costa Rica
The pressure is on Brazil to deliver in St Petersburg and although Costa Rica represent dangerous opponents, we expect the five-time champions to rise to the occasion and produce a performance worthy of a potential winner of this tournament.