Vicente del Bosque has created a formidable football machine that won the European Championship in 2008, the World Cup in 2010 in South Africa and a second European title two years ago. (Agencies)
Should Spain retain the World Cup, it would be the first time any country has sealed consecutive triumphs since Brazil in 1958 and 1962. They start in a tricky Group B however against the Netherlands, Chile and Australia.
And there is scepticism as to how long a squad of players that have won almost everything at club as well as international level can dominate.
Those fears were realised when a young and highly-motivated Brazil side destroyed Spain 3-0 in the final of the Confederations Cup last year.
"Brazil are the big favourites for me," goalkeeper Pepe Reina admitted recently.
Yet, Spain can point to their own experience in South Africa to prove that the dress rehearsal of the Confederations Cup isn't always the best indicator of how the World Cup will develop.
None of the winners in each of the previous four Confederations Cups held the year before a World Cup have been able to repeat their success when the stakes are raised 12 months on.
Indeed, Spain suffered a shock 2-0 defeat to the United States in 2009 before returning to conquer the world in 2010.
A slow drip of fresh faces into a highly experienced squad has also sparked optimism that this Spain side will have the requisite hunger to drive them to success once more.
The most noteworthy addition is that of Atletico Madrid striker Diego Costa, who completed his controversial conversion from Brazilian international to Spain's first-choice centre forward in under 12 months.
Costa was allowed to switch allegiance as he had only previously represented Brazil in friendly matches and could prove to be a huge asset for Del Bosque in one of the few positions where Spain are lacking in depth.
The emergence of Cesar Azpilicueta at Chelsea this season has made him the favourite to cover another problem position at right-back. Meanwhile, the Bayern Munich duo of Thiago Alcantara and Javi Martinez offer high quality reserve options in central midfield and defence respectively.
Given the draining conditions that all sides will encounter in Brazil, though, fatigue remains the biggest worry for the reigning champions.
On top of their commitments at international level, the majority of the Spanish squad have been involved in the final stages of European competitions for a number of years without a break.
This season is no different as all three of the country's best teams Barcelona, Real Madrid and Atletico Madrid cruised into the quarter-finals of the Champions League.
"The competitions are very intense, there are games every three days. All the games are hard and we have to be prepared in case we lose someone to injury," warned Del Bosque.
However, with their tournament know-how and depth of squad, Spain remain one of the most feared sides on show in Brazil.
As Del Bosque said after learning that his side will face the Dutch in a re-match of the 2010 final in their opening game, "I am sure they didn't want to face us as much as we didn't want to face them."
Vicente del Bosque has created a formidable football machine that won the European Championship in 2008, the World Cup in 2010 in South Africa and a second European title two years ago.