When Barcelona confirmed they had received a request from Lionel Messi’s lawyers informing them he wanted to terminate one of football’s longest-standing relationships, the owners of Europe’s biggest clubs would have raised a collective eyebrow.

It was akin to the Mona Lisa suddenly becoming available on the art market, such is Messi’s status in the game despite the fact that he is 33 and the magic might soon begin to fade.

Already the usual suspects are being lined up as Messi’s next club with, not surprisingly, a reunion with his former manager Pep Guardiola at Manchester City the most likely scenario according to the bookmakers.

There is talk of Messi joining forces with Cristiano Ronaldo, his long-term rival as the world’s greatest player, at Juventus or linking up again with Neymar at Paris Saint-Germain.

Inter Milan’s Chinese owners would also see Messi as the player to turn them back into a European force.

Amid fans’ anger with Barca president Josep Maria Bartomeu, sports channels and social media were buzzing with Messi’s Barca bombshell.

“We love you, Messi stay, Messi stay!” and “Bartomeu resign!” chanted several hundred fans outside Camp Nou.

Yet, it is by no means certain Messi will have multiple options if the split with the Catalan giants he joined as a teenager is irreparable.

Messi insists a clause in his contract allows him to leave for free — a scenario that would attract a frenzy of suitors.

Barcelona, however, say that clause has expired and a rival club must pay his release clause of 700 million euros ($826 million) if he is to leave without the club’s consent.

Should Barcelona stick to their guns, it would knock most potential buyers out of the ball park, especially with Messi’s one million euros per week salary demand.

The marketing men will point to the avalanche of shirt sales and Messi merchandising that the six-time Ballon d’Or winner would guarantee, not to mention his disciples around the globe swelling the club’s fanbase.

Finances aside, though, there is an even bigger question mark hanging over Messi. Is he a fading force?

It sounds churlish to suggest that of a player who remains the heartbeat of one of Europe’s biggest clubs for whom he has helped win over 30 trophies, but none last season.

On the other hand, a fresh challenge might spark a golden final chapter to his glittering career. The question is where?

Former club great Rivaldo thinks Guardiola could rebuild his team around Messi.

“Manchester City could be Messi’s best option as his next club. He’s 33 but his quality and talent are both unquestionable and I think he still has a few more years at the top,” Rivaldo said.

Barca hopeful

Barcelona though haven’t given up on Messi just yet. On Wednesday, the club reiterated that its restructuring project still revolves around the player.

“We want to rebuild for the future together with the best player in history,” Ramon Planes, the club’s technical director, said.

“We are not contemplating any departure on a contractual level because we want him to stay. We have to show a huge respect for Messi.”