I hope it's not a revelation to you that when it comes to football managers, the four apocalyptic horsemen are injuries, defeat, the sack and the transfer market.

The first will lead to the second. Injuries provoke an increase in dropped points. Accumulate enough defeats and the clattering hooves of the third will soon be heard. But the fourth, the transfer market, can look deceptively like he's mounted on a friendly, exquisitely-groomed, well-tamed thoroughbred until the beast rears its forelegs and thumps unsuspecting football managers full in the face. That's why it has been fascinating and uplifting to see how Zinedine Zidane and Ernesto Valverde trying to turn into horse-whisperers over the past 10 days, each of them actively battling the collateral damage the transfer market is trying to inflict on them.

The main actors in this theatre of defiance and risk, directed and produced by "Zizou" and Valverde, are Ansu Fati, Gareth Bale, Carles Aleña, James Rodriguez, Luka Jovic, Carles Perez, Vinicius Jr., Sergio Busquets and Sergi Roberto. Neither manager actually needs to lie in bed at night cold-sweating the arrival of the third horseman. They're not immune to being sacked, but they're also not currently in danger.

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Valverde has his critics, but he looks safe until his contract ends in June 2020. Zidane? In theory, given his brilliant champions league legacy as a player and coach, he should be the unsackable coach. However, on Tuesday, Marca, a newspaper consistently drip-fed information by Florentino Perez, splashed its front page with the headline "Zidane Loses His Immunity." Zidane and President Perez are in a battle of wills as to whether it should be Paul Pogba or Neymar shipped in before the transfer market closes next Monday.

If Marca plasters "Zidane Loses His Immunity" across their front page, to be seen or read by several million people around the world, it must be accepted as a rap across the knuckles from a higher office than merely the season ticket-holders. "Get your nose out of the Neymar affair, forget about Pogba and get the team playing better" -- that sort of message.

The first two apocalyptic riders, the pale and the red horses of injury and defeat, have visited Zidane and Valverde from almost the minute their summer holidays ended.

Madrid have been blighted by eight major injuries in 47 days, which crippled their preseason stamina-building, team understanding, sharpness and new-player induction. It was brutal for Ferland Mendy and Eden Hazard, new arrivals, while Real also bid goodbye to Marco Asensio for most of the season. Meanwhile, Barcelona lost Lionel Messi, Luis Suarez and Ousmane Dembele to a plague of muscle problems that would have sent many managers gibbering to a psychiatrists couch with claims that "life has got it in for me!"

These things, while either improved or worsened by a club's fitness practices, are largely out of the control of football managers. That particular horseman will visit: it's inevitable.

What about defeats? Madrid lost 7-3 to Atleti in New Jersey and Barça kicked off the season with a defeat for the first time since 2008. These things do damage managers, all of which means that studying Zidane and Valverde's decisions of who to pick or drop in their four matches, has been riveting for anyone who likes to people-watch in football and try to get under the skin of the main on-stage actors.

We've seen serious, ambitious but overburdened men making it crystal clear that they will embrace risk, that they will enforce principles, that they will stand defiant against certain club wishes... if it helps them deflect the damage the fourth horseman can inflict. The transfer market can become a pestilence for these two elite, seemingly untouchable and vastly successful men because it's a beast that they cannot outright control. No way. It leaves them fighting to become survivors, not victims.

Zidane wants Pogba this summer, though not only does it seem sure he's not going to get Manchester United's marquee player, but Perez doesn't appear particularly interested in trying to force a deal through. Zidane neither wants nor needs Neymar, sentiments that are of little or no interest to his employer.

Up front, Luka Jovic is far from the finished article as a striker. Zidane's assessment seems to be that Jovic has little in his locker beyond the fact that the young, burly Serb inarguably tucks away goals. But "suck it up, Zizou!" is the message from the big Bernabeu offices. This is who you're getting, regarding Jovic, so Zidane drops him.

As for Valverde? He'd love to be able to rely on Ivan Rakitic, one of his "most-used" footballers since the Basque (himself nicknamed "the Worker Ant") discovered the Croatian's unselfish, team-oriented relentless "all for one and one for all" playing ethic. But Rakitic is one of the few transfer-market coins that cash-strapped Barca have at their disposal.

The likeliest resolution is that Rakitic's stubborn insistence on staying will win the day when the market shuts on Monday. Meantime, the club's requirement that Ivan-the-terribly-good doesn't get injured, thus scuppering any possibility at all of putting him in a deal to secure Neymar, has been dominant.

Of Barcelona's 180 competitive minutes so far in 2019-20, Rakitic has only been given 45. Those only came while Suarez was already off injured and Messi was absent. In other words, in extremis. Valverde has had no choice. The point is this: when Valverde opted to deploy 16-year-old Ansu on Sunday he did so as if he was saying "I'm taking back control!"

The previous week at San Mames, he'd already ignored Sergio Busquets and Junior Firpo on the bench and given 21-year-old winger Carles Perez only his second-ever senior appearance. Then Valverde started the kid again at the Camp Nou in week 2.

Against Betis, when Ansu was made Barcelona's second-youngest player in club history, Valverde left on the bench two big-reputation (and big salary) players, Samuel Umtiti and Arthur, on the bench despite each of them crying out for game time.

Ansu may well be an emerging phenomenon and Perez a confident, talented young buck. But this was quite clearly a series of very firm messages. To President Bartomeu: "I don't need Neymar, I've got the super-kids and I'll use them." To the senior players who have been ignored: "It's time to sharpen up." To the unreliable Dembele: "Get professional or get ready to languish on the bench or in the stands." To the fans, media and to young academy players, including Ricki Puig, who some Barça media personalities and fans think is a mercurial genius already worthy of an automatic first-team place: "Youth will be trusted when I think it's time."

Zidane's decision-making in Madrid can be regarded as a little more pragmatic but like Valverde, it's still heavily laden with important declarations of self-determination, independence and potential conflict to come.

In order to have any chance of raising the cash to buy Neymar, Madrid's bean-counters would need to sell or trade James or Gareth Bale. Or both. Zidane may not have been terrifically keen on either man until now but the instant the Premier League market closed, he exercised some good old common sense and extended the olive branch of peace to the Welshman, who has since started both Liga matches and played all but fifteen minutes of the 180 available.

James, ripe to be sold or traded before the other major markets close next Monday, was picked on merit against Valladolid and played well; he wasn't wrapped in cotton-wool as Valverde has felt forced to do with Rakitic. The result? A good performance, but an injury now removes the Colombian as a trading piece from Florentino Perez's shopping basket.

Zidane took back control. The club haven't benefitted, but perhaps the team has. Perhaps he, himself, has. The manager's authority, his character and how he's viewed by the rest of the squad: all of those things have been reinforced. More, Zidane's decision to drop Jovic demonstrated his thoughts on the Serb's current form and preseason performances.

Cost: €50 million. The amount Zidane cares about that? Zero. It's a message to the striker, message to those who signed him. Oh, and as for Alvaro Odriozola, signed after Zidane quit Madrid in June 2018? He was dumped out of the squad altogether at the weekend.

Neither manager has won all his bets, and each has faced criticism. But both of them wrenched back the idea that "the buck stops with me and I'm not just flotsam or jetsam to be tossed around by the furies of the transfer market."

I think each man burnished his reputation, reaffirmed his authority, won back self-respect and faced down the fourth horseman of the apocalypse for football managers. How they must yearn to hear those hooves echoing into the distance next week.