Portugal and Ghana are both still in with a slim chance of progressing to the last 16 ahead of their final World Cup Group G clash in Brasilia, but will be relying on the outcome of the other match in Recife.
Germany and USA are three points clear of Portugal and Ghana and face each other as the group comes to a conclusion, meaning that a draw would be enough to take both sides through to the next round.
The two teams taking to the field at the Estadio Nacional are therefore not in control of their own destiny, but either Ghana or Portugal could still progress if there is a winner in the other game.
If Germany win, Portugal need to make up a five-goal swing while a USA victory would mean they need to recover an eight-goal deficit.
The chances are undoubtedly slim but manager Paulo Bento, whose contract runs until 2016, insists his job is safe whatever the outcome.
"What exactly do you want me to answer? If I'm going to continue with the team? I have repeated many times, the situation is very specific, very calm," Bento said.
"The federation trust me and the president trusts me, this goes way back.
"Whatever happens in the match against Ghana, I am not going to resign from my job as a coach, it's not my intention, it's not the intention of the federation staff or the president of the federation."
The Black Stars' best hope is for USA to lose, leaving them needing to win and turn round a two-goal deficit.
"Ghanaians have a strong mentality in football," said Ghana manager Kwesi Appiah.
"We always believe we have to fight to the end never mind what happens initially."
Portugal defender Pepe is available again after serving his suspension for a red card against Germany.
Full-back Fabio Coentrao is ruled out through injury while Hugo Almeida and Helder Postiga are doubtful.
Ghana right-back Daniel Opare is out injured and Sulley Muntari is suspended after collecting two yellow cards, meaning Michael Essien could make his first start of the tournament.