The tournament lost one of its outright favourites yesterday when Brazil were beaten by Holland. The attention is now on another one of the world's top sides, who have never been beaten by their South American opponents in three previous matches, which have ended in one win and two draws.
But Del Bosque said: "It is always the next match which is the most important. We have huge respect for what Paraguay has done and we certainly don't have the guarantee that it's going to be an easy match. You cannot be too optimistic to win, I mean there's so many teams on the same level, we certainly cannot already announce the result. So both teams will be in the same position, which is wanting to win and be in the semi-final."
With regard to Brazil being put out, the Spanish boss revealed it was not a massive surprise for him. He continued: "I don't think it's a lesson knowing the reality of football. We know that every match can be complicated. We start of on equal footing and the nature of sport is that anything can happen."
And he conceded that Spain's rise on the global stage over the past two years, which saw them crowned UEFA European champions in 2008, has brought with it further expectation.
He added: "I think this is a consequence of the position of Spanish football and I think Spain is in a good moment of its football history, so we want to play a good World Cup."
Opposite number Gerardo Martino, whose side have already made history by reaching the last eight for the first time, was predictably worried about facing such a talented team. But he said there were no easy teams at this stage, and targeted an interruption of Spain's passing game as one of the keys to success.
"Spain has so much ball possession that it forces you to defend," he said. "Teams have prepared a certain way of playing, but Spain still scored. They have ball possession 65-70% of the game and it imposes its style of play on you. We have to keep Spain from passing the ball. We have to move, show mobility up front, so that we can score goals."