If the stars align Portugal can still squeeze into the last 16 but Cristiano Ronaldo has already ruled out their chances of lifting the World Cup title.
With just one point from their opening two games and an adverse goal difference, Portugal are on the cusp of joining England and Spain in falling at the first hurdle in Brazil.
However, if either of Germany or the USA lose and Paulo Bento’s side beat Ghana by a sufficient margin, Ronaldo and co could pinch second spot in Group G.
They will have to do so without Fabio Coentrao, who is still out with a hamstring complaint, but Pepe returns from suspension after he saw red against Germany.
Strikers Hugo Almeida and Helder Postiga are both struggling to reach full fitness so Eder may earn his first start of the tournament alongside Ronaldo, who is still nursing a knee problem – and not expecting fireworks.
“Maybe we are an average team,” said the 2014 Ballon d’Or winner. “It would be a lie to say that we are a top team. We have a very limited team and we are not at the best level.
“This does not enable you to beat top teams. There are no miracles. We knew we would have a tough group, with perhaps teams better than us.
“I am not a hypocrite – I never thought we could be world champions, we have to be humble and know our level.”
Ghana are three goals better off than Portugal but, also sitting on just one point, they equally need a victory as well as hoping either Germany beat the USA or suffer a heavy defeat themselves.
The Black Stars are without a clean sheet in their last six World Cup games but Portugal – despite possessing one of the most potent players on the planet – have failed to score in six of their last nine.
Coach Kwesi Appiah will be without Sulley Muntari, which may see former Chelsea man Michael Essien come into the midfield, while Kevin-Prince Boateng should retain his starting place.
However, Muntari’s suspension is not the only disturbance to the pre-match build-up after the country’s government were forced to fly $3million to Brazil this week.
The money was sent on Tuesday to settle the appearance fees of a number of Ghanaian players who almost boycotted the trip to Brasilia.
An official statement from the Ghana FA said: “We wish to assure the general public following President (John Dramani) Mahama’s intervention the Black Stars are in high spirits ahead of Thursday’s match last Group G match against Portugal.”