When the transfer window closed on Monday, Madrid had finished a second consecutive window without signing anyone while Barca coach Ronald Koeman was told the club could not find even three million euros for a much-needed central defender.

"What I want as a coach is not possible financially," said Koeman in September.

To ease the strain, key players could be sold, their wages shifted, and those that stay may have to take further pay cuts. But gaining traction too -- from the two clubs at least -- is the idea that the coronavirus pandemic has made a European Super League a necessity.

"We are all aware how difficult these times are and the challenges we face in the coming months," said Real Madrid president Florentino Perez at the club AGM in December.

"Football needs new ideas to make it more competitive, more exciting and stronger."

A breakaway Super League "will guarantee the future financial sustainability of the club", said outgoing Barca president Josep Maria Bartomeu in October.

The pandemic has hit Barcelona and Madrid hard, certainly harder than their rivals in the English Premier League where bigger television contracts and billionaire owners have provided some degree of immunity.

Problems accentuated by pandemic

By the end of this season, Barcelona expect to have surrendered close to 500 million euros in revenue due to coronavirus and Madrid around 400 million.

Yet many of the burdens have been accentuated, not created, by Covid-19.

Madrid's 575 million-euro renovation of the Santiago Bernabeu and Barcelona's 800 million-euro plan to add seats and a roof to the Camp Nou are long-term projects.

Barcelona already had the highest wage bill in Europe before coronavirus came along. Real have been hamstrung in the transfer market since spending 350 million euros on new signings in 2019.

"Barcelona, especially, have been like this for a while," says Dr Dan Plumley, a football finance expert at Sheffield Hallam University.

"The finances have been day-to-day, hand-to-mouth, always operating on the edge."

When the pandemic is over and revenues return, the expectation is Barcelona and Madrid will also be among the quickest to bounce back.

While Barca's losses for last season were the worst in Spain, they were not alone in Europe.

Roma, AC Milan and Juventus in Italy all reported huge losses, while Manchester United last year reported net debt of 474 million pounds ($648m) early in the pandemic.

And Barcelona topped the latest Deloitte Football Money League with revenue of 715 million euros in 2019/20.

"So if a club has that income and owes one billion euros, is it balanced? It's not perfect but it can be restructured. The level of debt is exaggerated," says La Liga president Javier Tebas.

- A useful excuse? -

If a Super League is the aim, the pandemic is a useful excuse, a way of justifying what Joan Laporta, favourite to succeed Bartomeu as Barcelona president, has estimated would be an 800-million euro reward just for entering.

"Both clubs are playing the game," says Jimmy Burns, author of several books on Spanish history and football in Spain.

"Florentino is a hard-nosed businessman and history has shown Real Madrid and Barcelona are never afraid to push their own agendas."

"Financially, it's not something they need," adds Plumley. "Their need is to get bigger and to extend the gap further."

However, on the pitch the gap has rarely been smaller.

This season Madrid have already lost to Cadiz, Alaves and Levante as well as third-tier Alcoyano in the Cup. Barca and Madrid are 10 points behind Atletico in La Liga.

And while the dip in Spain is surely temporary, authority in Europe may be harder to recover.

Barcelona's historic 8-2 loss to Bayern Munich last season came after Real lost to Paris Saint-Germain and then Manchester City, two state-owned clubs whose riches continue to disturb the old hierarchy.

It is a problem that requires urgent action. "Both clubs have a huge history, mixed with a specific culture and politics, which creates a mystique," says Burns.

"But the reality is Barcelona and Real Madrid over the last 20 years have signed up completely to big business football as a global phenomenon. The Super League is just the natural evolution of those ideas."

ta/as/dj