Liverpool is having an exemplary season, apart from The Big Thing that we're not supposed to talk about. Even as a treble begins to look like a genuine possibility in Arne Slot's first campaign, the future of three of his key players remains in serious doubt — and a Real Madrid transfer policy could influence where Trent Alexander-Arnold ends up.

Along with Mohamed Salah and Virgil van Dijk, Alexander-Arnold is out of contract in the summer. Of the three, his situation appears most grave, in the sense that a very clear alternative to re-signing at Liverpool has made itself known: Real Madrid.

As it happens, Alexander-Arnold has also probably been the least integral of the trio to Slot's early success, although his age and quality would still make a free transfer departure a bitter blow. Whether the academy graduate can truly bring himself to walk away from Anfield remains to be seen, although the signs are ominous.

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Even for someone in his position, the vice-captain of his boyhood team, the appeal of Real Madrid is somewhat understandable. Alexander-Arnold has won everything at Liverpool, and a move to the Spanish capital would all but guarantee some more success in a new footballing culture, not to mention a link-up with close friend Jude Bellingham.

From Real Madrid's perspective, the draw of a transfer is even more clear. Dani Carvajal will return from a serious injury by the start of next season — and he signed a contract extension shortly after suffering the setback — but he is 33, and the club will be on the lookout for a long-term successor.

Even if money were no object, Alexander-Arnold is arguably the best right-back around, and surely the most technically gifted. The opportunity to sign him on a free transfer, at a time when strengthening in his position is high on the agenda, makes complete sense for Carlo Ancelotti's side.

Concerningly for Liverpool, it also apparently fits into a new transfer policy instigated at Real Madrid. It has been termed "all or nothing" by insiders.

According to The Telegraph, it refers to an approach where Los Blancos will sanction massive outlays on key targets, but limit itself to the most appealing free transfers when conducting the rest of its business. Bellingham represents one end of the strategy, with Alexander-Arnold at the other.

Of course, precious few clubs are in a position to execute this method. Real Madrid has the luxury of being able to splash out $143m (£115m) on someone like Bellingham at the drop of a hat — and even more importantly, it has the pulling power to turn the head of almost any player nearing the end of their contract.

Alexander-Arnold would be the latest in a sequence that includes Kylian Mbappe, Antonio Rudiger and David Alaba, all of whom came to the Bernabeu for nothing. That would be a quite remarkable quartet.

It goes without saying that "free transfer" is a misnomer, and that Alexander-Arnold could join the others in enriching himself even further with a frankly obscene signing-on fee. Even so, Real Madrid has clearly made the calculation that this is still a highly cost-efficient way of securing top stars.

For its part, Liverpool has not given up on being the one to buck the trend, convincing Alexander-Arnold that his future involves taking over the captaincy at Anfield and becoming an all-time great. But the new transfer approach at Real Madrid will ensure its approaches become more insistent than ever as the summer draws closer, so Slot may have to strap in for more uncertainty as the season approaches its climax.