Inter made exoticism a trademark of the way they assembled squads long before most of Europe's elite clubs were exploring distant frontiers in the search for talent. The Inter line-up that took on Napoli in the joust for second place in Serie A at the weekend had, predictably, more South Americans than Europeans in it; that ceased to be newsworthy several years backs when Inter fielded teams without a single native Italian in them.
Less welcome for the Inter image over the past two decades was the ready association it carried with economic excess: splurges on transfer fees and salaries, oversized squads, all against the backdrop of a 17-year gap between domestic league titles.
Athletic, by contrast, are a unique island in 21st century professional sport, football's equivalent of the stallholder exclusively cultivating his own produce while vast hypermarkets crowd around him.
Athletic, famously, employ and nurture only footballers with a Basque background. They rarely pay hefty transfer fees, and though ambitious, maintain their support base not because they flaunt flamboyant signings but because of their powerful identity. No major club in Europe has a more defining sense of locale.
So to see Inter and Athletic coupled as antagonists in what is a rare public call to arms by an organisation claiming to represent the well-being of the sport, its fair balance of interests, might seem a paradox.
When Fifa or continental confederations such as Uefa or the Asian Football Confederation ponder these issues, they usually applaud models like that of Bilbao, or that of Barcelona, who spend plenty on recruitment but have enjoyed great success lately using mainly players from their own academy. The confederations like the way those clubs create a sense of community with supporters and show the way to fiscal sanity for a game that needs urgently to rein in its spending.
Yet the international professional footballers' union, FIFPro, have just condemned Inter and Athletic with the same broad brush, citing them as examples of what FIFPro calls an "alarming" tendency among club employers to "bully" their workers.
The cases of Inter's Wesley Sneijder and Athletic's Fernando Llorente are distinct in details, but both players have recently rejected contract extension offers from their clubs and, since doing so, become marginalised from the first team.
FifPro are absolutely right in sensing the recent non-selection of both players has as much to do with an economic stand-off between boardroom and individual as with what Sneijder and Llorente can bring to their teams as players.
Theo van Seggelen, secretary-general of FIFPro, suggested last month that Fifa charge Inter with "unsporting conduct" for their treatment of Sneijder, who is currently on a contract paying not far short of US$300,000 (Dh1.1m) a week, which he signed in 2010, shortly after helping Inter to the treble.
In the summer, Sneijder was asked by Inter to reconfigure the terms, so that his monthly wage would be reduced but the length of his deal extended to 2017 rather than 2015.
He has not agreed and he has not been picked by coach Andrea Stramaccioni since September.
Van Seggelen talked of "blackmail" in the case of Llorente, who turned down a new contract at Athletic, where the striker has scored 115 goals in 310 appearances. His present deal expires in June; he has a buyout clause, until then, of €29m.
The Athletic coach Marcelo Bielsa insists Llorente, 27, will remain part of his squad until the end of the campaign. Yet all parties know that if Athletic are to receive any transfer income from the player, he would have to move clubs in the one remaining window between now and the end of the season, the one that opens in 18 days.
A few years ago, Sneijder and Llorente would have been deemed to be holding all the aces in their situations, ready to call a stubborn club's bluff in wage talks, armed with an array of offers from elsewhere.
These are two men who were participants for the finalists, Holland and Spain, at the last World Cup, stars with many elite admirers. But in times of wide economic recession in Europe, and a degree of nervousness over the real implications of Uefa's Financial Fair Play guidelines, which could in future penalise clubs whose accounts do not reflect a sustainable balance between income and outgoings, attitudes among employers have hardened.
The last winter transfer window provided evidence. A year ago, the lead-up to January 2012 was dominated by the name of Carlos Tevez.
Here was another gifted, highly paid footballer at odds with his club, sidelined from first-team action at Manchester City, supported by his union, the English PFA, after he was given a maximum club fine for apparently refusing the instruction of his coach, Roberto Mancini, to take part as a substitute in a Champions League match against Bayern Munich.
Mancini and City considered Tevez's relationship with club severed, and put him on the market. What they then found was the market, even for a talent like Tevez, would not yield to his and their financial expectations.
Clubs that might normally have auctioned vigorously for his signature had become more circumspect.
Among them Inter, whose enthusiasm for adding Tevez to a squad struggling to keep up in Serie A 11 months ago would be tempered by what has become a very explicit policy of cost-cutting. In the past 18 months, high earners such as Samuel Eto'o, Julio Cesar and Maicon have all left the club, part of a drive to bring down overall salaries. AC Milan, with the same aim, have ushered out several long-serving players.
Unsold last January, Tevez eventually returned to a City set-up where he still features prominently. With no exit available, player and club took the pragmatic route. Perhaps Llorente, who has been jeered by Athletic fans - he is used mainly as a substitute, if at all, by Bielsa - will begin to figure in more starting XIs if he stays in the Basque Country until June. Sneijder might yet return to prominence as an Inter player.
Their names will still animate the forthcoming transfer window. And their status, come February 1, should provide a strong clue about how cold the economic climate in football really is, and whether power might just be shifting from players to employers.
Five deals to stir the January transfer market
Two and half years after joining Real Madrid for more than €55 million (Dh263.4m) from AC Milan, the Brazilian, winner of the 2007 Ballon d’Or, is available, at a price, and certainly at a vast reduction on what Madrid paid for him. He has started only one league match this season.
Marginalised by Inter Milan, who he helped guide to a treble in 2010, because he has stalled over their offer of an amended contract, the gifted Dutch international attacking midfielder, 28, is widely admired across Europe, though his salary expectations are steep.
The former England captain and global brand has come to the end of his contract with the LA Galaxy but seems determined to continue playing, even though he turns 38 in May. Paris Saint-Germain’s interest of a year ago has cooled, though Ligue 2’s Monaco are keen.
The Portugal winger has fallen from favour at Manchester United, who were ready to accept a handsome offer from Zenit Saint Petersburg for him in the summer. That deal fell through because of wage demands. Nani is currently recovering from a hamstring problem, and United will in the meantime listen to offers.
World Cup winner in 2010, European gold-medallist in 2012, the striker brings a potent mix of physique and fine touch but is sidelined due to a contract dispute at Atheltic Bilbao. The club know if they don’t sell him next month, he walks away for free.