That, according to Calderon, who was Real supremo from 2006 to 2009, would automatically get a boss bullet if he was at the Bernabeu.
The Spaniard, 62, said: “I’d change the manager if Real Madrid finished sixth and failed to reach the Champions League the next season. Of course I would.
“It’s a real disaster in every sense not to be in Europe. Not only in terms of the money you get from playing in the competition but from all your club sponsors.
“Sponsorship deals are linked to the Champions League because of the exposure it has on TV. All deals are affected by being in or out of it of Europe. No question.
“I’m sure there’s no difference in the contracts of Real Madrid and Manchester United.
“They will have to deal with losing as much as £100million - both in lost television rights and the reductions in sponsorship money."
That’s why the club’s financial supremos – led by relatively-unknown Richard Arnold, will decide Moyes' future.
Forget ambassador Sir Alex Ferguson, who along with Sir Bobby Charlton and David Gill, forms part of the club’s ‘football’ board.
For it is the likes of managing director Arnold, who haven the real power to force immediate change in the Old Trafford dug out.
Arnold, 41, is on the main board and a hugely-influential voice among the corporate hierarchy as he is responsible for the club’s fast-growing global empire.
His advice is all-important to American owners, the Glazer family. If he thinks Moyes must go, the NFL tycoons are likely to act.
And it is the potential damage form on the pitch is doing to the revenue streams around the world which will ultimately dictate whether United stick or twist.
United’s share price on the New York stock exchange is still close to an all-time low amid a string of shocking losses under Moyes.
Shares were trading at around £9 last week, way below their 52-week high of £12 in May 2013.
Now the club, and Arnold in particular, are waiting to see what happens on Wall Street in the next month as Moyes tries to revive the team’s fortunes.
But with more than £250m wiped off the club’s value in eight months – it was worth £1.53billion close of play Friday - investors and sponsors are looking for a dramatic recovery.
Should that fail to materialise, Moyes, no matter his support from predecessor Fergie - who handpicked him for the job – is at the mercy of the money men.
That’s where Arnold comes into play as he oversees the running of one of the planet’s mostprofitable sporting institutions.
The financial high-flier had no previous links with football before emerging on the Old Trafford scene.
Twice nominated for ‘UK young director of the year’, Arnold was appointed United commercial director in 2008.
And his remarkable success in that role - against a backdrop of world economic recession - earned him a place on the board and promotion to Group managing director last March