Brazil and Italy will face off for the honour of top spot in Group A at the Confederations Cup (Live on RTÉ Two, RTÉ.ie from 7.30pm).
The two teams have already secured their place in the semi-finals of the tournaments by beating both Mexico and Japan in their previous outings, and will effectively be playing for the right to avoid the in-form world and European champions Spain in the next round.
Italy coach Cesare Prandelli has problems in midfield to sort out before going into the game. Veteran playmaker Andrea Pirlo will miss the match with a muscle injury.
"We had an MRI that shows a calf strain," said Italy doctor Enrico Castellacci.
"He will not play against the Selecao and now we have to work with him ahead of the semi-finals."
Also missing will be Daniele De Rossi, who is suspended after collecting two yellow cards.
There is greater pressure on Brazil, who are playing against the backdrop of the home fans' expectations, as well as the extensive protests which have been held against the cost of hosting next year's World Cup.
With this match to be played in the capital Brasilia, scene of extensive protests in the past few days, there is the potential for further flashpoints.
However, Brazil's players are trying to focus on the pitch, and they are keeping things light-hearted.
Playmaker Oscar, 22, may not have had too much experience of facing Italy's veteran goalkeeper Gianluigi Buffon in person, but he thinks he has the Juventus man figured out.
"I've seen Buffon play since I was a kid, and I've played against him a lot on video games," he said.
"I've been lucky against him and I hope I can make this happen on the pitch."
Live coverage of Italy v Brazil from 19:30 on Saturday 22 June and Nigeria v Spain from 19:30 on Thursday 20 June on RTÉ Two and RTÉ.ie (RoI only)