(CNN) -- Spain's football duopoly of Real Madrid and Barcelona has become so dominant that sponsors have lost interest in backing other Spanish clubs.
"Having two monsters like Real Madrid and FC Barcelona, the world's leading concert in football, overshadows the other clubs," financial expert Jose Maria Gay de Liebana told CNN.
"Sports sponsorship companies are more inclined to be the third or fourth sponsor of these two great clubs, Barcelona and Madrid, rather than be the first sponsor of a club without universal screening," he added.
Gay de Liebana told CNN that the apparent advantage of having global brands in the top tier of Spanish football -- known as La Liga -- is in fact a serious detriment to many clubs.
According to Forbes Magazine's 2012 rankings, Real Madrid is the richest club in the world by revenue -- $695 million -- and second only to Manchester United in market value.
Meanwhile, Barcelona -- widely recognized as the best football team in the world with a pedigree of stars such as Lionel Messi and Andres Iniesta -- is the second richest club in the world by revenue.
Gay de Liebana says the presence of these two football behemoths combined with billions of euros of debt - estimated at $4.5 billion for Primera Division teams -- and liabilities has meant Spanish football clubs can no longer cope with this burden.
Traditionally local governments in Spain have had a role to play in the financial management of football clubs. In the past, teams such as Valencia and Madrid, as sporting institutions, have received subsidies from local authorities, according to Spanish football expert Sid Lowe.
But in the current economic climate, state investment in football clubs is not a high priority for many politicians as the central government in Madrid grapples with a spiralling national debt and chronic unemployment of over 25%.
Spain -- the eurozone's fourth largest economy -- is likely to be the next bailout casualty of the debt crisis in the 17-nation currency union.
The government in Madrid has already requested a rescue package for its ailing banks, which require almost 60 billion euros ($76.4 million) in support following an audit in September.
Real Oviedo's plea
Further down the feeding chain of Spanish football the financial situation is even more dire -- so much so that one Spanish club in the third division -- Real Oviedo -- has turned to football fans for help.
Earlier this month the Asturias-based team launched a campaign, whereby fans could effectively buy shares at approximately 11 euros [$13] each in exchange for a token stake in the club.
Word of Real Oviedo's plight went viral on Twitter and football fans across the globe responded by purchasing shares and raising more than one million euros ($1.2 million) in nine days.
Gay de Liebana argued that the current state of Spanish football clubs is the result of poor financial regulation and supervision.
When asked whether other teams might also stand on the precipice of extinction, he said: "I absolutely know it will happen... The next few months -- and I hope I am wrong -- will be tragic for some clubs."