The world champions' chances of defending their crown in Brazil next year have been compromised after Friday's 1-1 draw against Finland in Gijon left them trailing France by two points at the top of European qualifying Group I.
Now, there is serious pressure on Del Bosque's side to get a result at the Stade de France, with the consequences of a defeat potentially very serious indeed.
Lose, and Spain would likely need to resort to a two-legged play-off to stand a chance of making it to Brazil.
Nervous Spanish media have started to question the team's style after watching them fail to score more than once against limited Finnish opponents, and ultimately pay the price.
That result followed a 1-1 draw against the French in Madrid last October.
Del Bosque, however, is confident that Spain will be able to take advantage of the space afforded them by a France team set to attack far more than Finland.
"We are not anxious at all," he said at an eve-of-game press conference at the plush Hotel Bristol in the French capital on Monday.
"It is logical to reflect after what has happened in our last two games. Despite dominating completely we couldn't score more than once, so it is understandable that people will have doubts.
"But we mustn't get nervous, we must stay calm, open up the pitch and use the width.
"We do need to find solutions but this will be a much more open game."
Given their unprecedented recent success, Spain have every right to be confident in the face of a couple of minor setbacks.
But Del Bosque was full of praise for a France side that, while not exactly transformed under Didier Deschamps, have steadily improved since last summer's European Championship, when they lost 2-0 to Spain in the quarter-finals.
"They have players with pace and the ambition to play football," said the 62-year-old Del Bosque.
"There are talented players such as (Karim) Benzema, (Franck) Ribery, (Yohan) Cabaye, (Mathieu) Valbuena. They have power in the full-back areas too, and are a very good team.
"When the draw was made we knew France would be very difficult opponents for us. They have quality, experience and know how to play games like these."
Del Bosque is hopeful that midfield duo Xabi Alonso and Xavi Hernandez will be able to play, and is also set to keep faith with Sergio Ramos in central defence, despite suggestions from some quarters that the Real Madrid man should return to right-back.
"I think he is fine where he is," he said of Ramos, who won his 100th cap against Finland, a remarkable achievement for a player who is still just 26.
"(Alvaro) Arbeloa has done a good job on Ribery there, whether at the last European Championship or in the game in Madrid, so we have no fears about him
"And the pairing of Ramos and Gerard Pique is one of the best in Europe, so why change it," he added of his central defensive partnership.