Cape Town - Liverpool striker Fernando Torres says Spain has yet to find its best form, forecasting greater things to come for the European champions.

Spain line-up against their Iberian arch-rivals Portugal on Tuesday in an eagerly-anticipated round of 16 clash, with the winner facing either Paraguay or Japan in the quarter-finals.

Torres - who is yet to score in the tournament - said anxiety prevented them from playing their usual brand of football until now, which has seen them suffer a shock 1-0 opening game loss to Switzerland before beating Honduras 2-0 and Chile 2-1.

"The boss wants us to rediscover our usual form," he told fifa.com.

"We still haven't shown our best form or hit the heights we were hoping for. I think it has to do with the defeat against Switzerland.

"The fact we needed to win our subsequent games, along with the anxiety that brings, stopped us playing the way we would have liked.

"But now we're at the stage we'd aimed to reach before we came here. We managed to top our group and now it’s up to us to play the football we enjoy playing. We're certain that the team’s going to get stronger."

Coach Vicente Del Bosque made it clear on Monday that the entire Portugal team was dangerous and Torres said he had told the players to operate more as a unit.

"I think that we didn't press aggressively enough in our previous games. We didn’t play close enough to each other," he said.

"We need to play more as a unit, especially against teams like Portugal who are very strong defensively and will wait for us to bring the game to them.

"They've not conceded a goal yet in South Africa, so a team like that will be very tough to break down.

"What's more, they've got very dangerous forwards like Ronaldo and Simao. That means a counter-attacking game would suit them, so that’s something we’ve got to avoid."

The Cape Town clash is the two teams' first meeting at a World Cup, but the pair share a lengthy footballing history featuring no fewer than 32 previous matches.??

Spain have the edge with 15 wins to just five victories for Portugal.?

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