How Zinedine Zidane is clearing path for son Luca to be Real Madrid's No 1

Luca Zidane (left) and his father Zinedine. (Photos: REUTERS/Juan Medina/AFP/PIERRE-PHILIPPE MARCOU)

It eventually helped spark Zinedine Zidane's decision to walk away from the club, and now it looks like it will mean the beginning of the end for either Keylor Navas or Thibaut Courtois at the Santiago Bernabeu.

Let's start at the beginning: Fifteen months ago, Real Madrid arranged to buy Kepa Arrizabalaga from Athletic Club in that winter market for a mere €20 million.

This is the guy, remember, who went on to become the most expensive keeper in history when signing for Chelsea for €60m more only nine months later.

Back in January 2018, Kepa's contract was in its last six months. He was free both to sign for a rival club in summer at no cost and to begin direct negotiations with whomever he wished. Effectively, for Kepa's suitors, this was the Christmas sales.

Madrid buying him there and then at a knockdown price seemed terrifically good business: young, talented, familiar with both La Liga and European football, even if not hugely experienced, ready to be of use immediately, and a way to ensure that nobody else picked him off for free that summer.

It has been widely reported, and I trust, that the preparatory medical already had taken place by the time that Zidane, asked specifically about Kepa in a prematch news conference on Jan 6, stated: "I don't need a keeper."

He went on to specify that, midseason, he saw no need to mess about with the three goalies who had begun Real Madrid's season: Keylor Navas, Kiko Casilla and a certain Luca Zidane.

His words caused major ripples in the pond. If it wasn't outright defiance, then it was pretty damn close.

Effectively, this was the first public evidence of the severely different views held by Los Blancos' president and their coach on Madrid's imminent transfer market tactics.

Florentino Perez doesn't like being contradicted in public, not even by his beloved Zidane.

The next ripple? On understanding that Zidane refused to sanction his arrival, Kepa renewed his contract with Athletic, improving his immediate salary, thus assuring that both he and his club would receive vastly better terms if he was transferred in the summer of 2018. Which is precisely what happened.

The third ripple was that Perez, unwilling to be defied, intensified his attempts to contract Courtois, in a deal that would eventually cost Madrid around double the January 2018 price for Kepa: €40 million.

The whole business - Perez not agreeing with Zidane on who to sign, who to sell, who to promote - played its part in Zidane's 180-degree change of stated position that he would be "delighted to extend his contract and stay with Madrid for years" to walking out on the club just a handful of days after winning the Champions League against Liverpool.

The Frenchman decided to let Perez find out the relative balance of which of them knew more about football. It was a comparison that left one of them short.

Before returning to the appearance of Luca Zidane this weekend in Madrid's laboured 3-2 win over bottom club Huesca, let's just take a magnifying glass to the intricacies of the Kepa moment in January 2018.

It was, by then, already time for Casilla to move on. Navas was hugely loved and trusted by his coach and the squad but, even then, Perez's long-standing wish to improve was an established fact - evidenced by David De Gea's near arrival, Kepa, and previous flirtations with Courtois.

Whether or not you rate Kepa as a world-class prospect, Madrid's move for him added up from a business perspective. Here was a promising, talented, young Spanish keeper with no need to adapt linguistically or culturally, and at a succulent price - a bargain-basement price, in fact.

If Madrid's third keeper at that time hadn't been the son of a powerful coach, sharing the name Zidane, he would unequivocally have been told: "You're promising, your time will come ... but right now, it's just tough luck, son." Back to full-time duty with Castilla or out on loan.

Navas would have remained No 1, Casilla would have been told he was now third choice and that he had better start thinking of where he was going next and Kepa, as the new backup, would have been given the remaining Copa del Rey matches - which feasibly could have been all the way to the final, which Barcelona eventually won.

But the fact was that if Kepa had been signed that January, it was none other than Luca Zidane under threat.

Now I don't think that it's either wrong or suspicious for an ultra-successful, ultra-powerful coach like Zidane to be protective or ambitious on behalf of any of his sons. Particularly if he genuinely feels that they are very talented.

I'm told, by someone who consults with the club's president, that Zidane is obstinately determined that Luca is given the opportunity to prove himself at Madrid.

And why shouldn't he be? Nobody in Italy bears a grudge against the late Cesare Maldini for giving his son Paolo an Italian U21 debut in 1986, right?

Ditto Harry Redknapp for sticking his nephew, Frank Lampard, in the West Ham team when there was notable opposition from suspicious supporters. That kid turned out to be decent, no?

At Ajax, there won't be any quibbles about Daley Blind, quadruple title winner, making his debut for the club when his dad, Danny, was director of football.

Nor did Kasper Schmeichel win the Premier League and thrive internationally thanks merely to sharing a surname with his father, Peter.

But if you had been in the crowd 10 days ago at Madrid's Alfredo Di Stefano Stadium when Castilla drew 0-0 with Ponferradina, you, like Zidane, would have witnessed young Luca pulling of a wide range of truly first-class saves against Yuri de Souza, Edu Bolanos and Alex Aizpuro. It was one of three straight clean sheets that Luca had kept for Castilla. He had been on form.

Courtois' minor injury picked up playing for Belgium, plus Navas only training fully once after Costa Rican duty in Central America, in addition to a long transatlantic flight home, meant that resting one and benching the other left Luca in pole position - at least in his dad's mind.

I'd guess that Navas, having played just 1,400 club minutes this season - slashed by more than two-thirds as compared to the same stage in the 2017-2018 season - won't have been impressed.

Perhaps the manager was sowing the seed that it's the Costa Rican, rather than Courtois, who should be preparing to seek new pastures in the summer.

Message received, Keylor? We shall see.

All that's crystal clear, right now, is that Zidane believes Luca is a proper keeper and potentially a first-team prospect for Real Madrid - whatever anyone else might think.

This article first appeared on ESPN.com.