Los Blancos president Florentino Perez is nothing if not persistent, and many other Galacticos have fallen for his charms and a great deal of cash in the past.
In Luis Figo, we have the most famous example of a player crossing the Barca-Real divide, with Ronaldo and Luis Enrique two others to have turned out for both clubs.
It isn't a new phenomenon, and if the deal is right, it happens.
And just how much must it grate on Real's chief that despite spending a Sky Sports-reported €1.2 billion to bring some of the world's best players to the Santiago Bernabeu, Los Blancos still trail in the slipstream of the Blaugrana.
A Press Association report (via the Guardian) detailed that:
The Partido de las Doce programme on the Cadena COPE radio station claimed representatives of Real approached the Argentinian in 2011, 2013 and 2015, but were rebuffed on each occasion.
Each attempt to prise the Argentinian genius from his second home appears to have tied in with certain events too.
Perez should've realised as long as five years ago he was barking up the wrong tree, though.
Per Sky Sport Italia (via Salvatore Landolina of Goal), Messi explained during 2011 that: "I will never go [to Real Madrid] or to any other teams. ... I always want to stay here, finish my career with Barcelona and then maybe play in Argentina. I would like my European career to be around here."
That's a fairly unequivocal statement leaving no room for misinterpretation.
Since then, the Blaugrana have continued to go from strength to strength, while Real's trophy haul has paled into insignificance.
Per Real's official website, Los Blancos have secured one Champions League trophy, one Club World Cup, one European Super Cup, one La Liga, one Copa del Rey and one Spanish Super Cup.
Barcelona by contrast, per their official website, can boast two of each of those trophies bar the Champions League.
Moreover, at the time of writing, they look well placed to win yet another Liga, are in the semi-finals of the Copa del Rey and remain favourites to become the first side to retain the Champions League in its modern guise.
No amount of money would sway any player from moving away from that sort of success at club level unless there were other factors to consider—for example, if they weren't getting enough games a la Marc Bartra.
That doesn't apply to Messi, of course.
Furthermore, there's an overriding feeling that although there are many egos in the Barca dressing room, Enrique has harnessed these well enough to ensure they play as a team at all times rather than the collection of individuals Real Madrid often appear to be.
The spectacular dovetailing in attack of Messi, Neymar and Luis Suarez is simply unlikely to be replicated in a Real Madrid front three that would potentially include Gareth Bale and particularly Ronaldo.
Sorry, Florentino. Money can buy you many things but evidently not the one thing you truly desire. Not now. Not ever.