Highlights - Paraguay beat Japan on penalties
Paraguay coach Gerardo Martino insists his team will pose a threat to Spain despite scoring only three goals on the way to the World Cup quarter-finals.
Martino's side beat Japan on penalties to reach the last eight and will now face the European champions.
"In three of the four World Cup matches we had to take the game to our opponents and that's difficult for a team like ours," said Martino.
"Our future rivals will let us play. Spain will give us more space."
Paraguay's success so far has come courtesy of a disciplined defence which has only conceded one goal in the tournament.
And even if Spain do give Paraguay the space Martino craves, goalkeeper Justo Villar insists the South American side will not return the favour.
"Our football has always been about a lot of hard work and tactics," said Villar.
"It's going to be a good match where you will see two types of football.
"One side trying to attack skilfully while we try to stop them and then try to take advantage of our chances."
Martino insisted the triumph over Japan - which took Paraguay into the quarter-finals of the World Cup for the first time - was fully deserved.
Oscar Cardozo converted the decisive spot-kick as Paraguay won 5-3 on penalties after extra time in a scoreless stalemate in Pretoria.
Martino added: "It's never nice for a match to be decided in this way but I think we sought the win a little more.
"I think we were lucky in the penalty shoot-out. That made the difference."
In a tight encounter chances were few and far between but Martino was just happy to have progressed to the next stage of the tournament.
"Perhaps it wasn't the match people wanted to see but I don't think either team has anything to reproach themselves for.
"When you look at how the players played, the solidarity they showed, their enthusiasm, their will to make the history books, both teams did it the same way.
"To speak of an achievement in getting to the quarter-finals is all right but to consider this my greatest achievement is, I think, a bit premature."