"It (familiarity with the pitch) can help us. I can say that during the World Cup this is home for us," Queiroz told reporters on Monday.
"With the win and the performance against North Korea, I think it is probably important to say to Spain that Portugal is going to play at home in Cape Town," he added.
The thumping of the Asian side was Portugal's only win in Group G, their other two games ending in goalless draws against the Ivory Coast and Brazil.
A bid by the Portuguese to protect their favourite turf by training a few kilometres away at Athlone Stadium fell flat when FIFA allowed the Spanish to train at the match venue.
Queiroz believes, however, that both sides have an equal chance of winning the Iberian duel.
"Spain have a good team with much balance and a recent tradition of good results including their European Championship win in 2008, but we also have a good team and attacking players that can give any team a headache," he said.
Cristiano Ronaldo is certainly one of those players, and Queiroz said the world's most expensive player may yet confound his critics by snatching a trophy at the end of the season.
"I don't agree with the idea that he didn't win anything this season, because his season is not over yet. We have a title to fight for, so let's see," the coach said.
Queiroz said midfielder Ruben Amorim will miss the match after failing to shrug off a thigh injury. Winger Danny, who also has a thigh injury, is still doubtful for the game, as is left back Duda with a groin injury.
Seven Portugal players, including Ronaldo, picked up yellow cards in the group stage and could miss the quarter-finals if they are booked against Spain, but Queiroz said that will not affect their commitment.
"They will have to play openly. There will (be) no special care in this game about yellow cards, we have to give everything we have to move ahead in this competition."
