The 33-year-old has informed the club he wants to leave in a move that has stunned the football world.
Remarkably, he could walk away for nothing and would evidently have a free pick for his next destination.
In his long-running battle with Cristiano Ronaldo for GOAT status, Messi is often criticised for not having plied his trade outside of his Camp Nou comfort zone.
But could leaving the Catalan giants tarnish Messi's legacy? We look at how other legends who moved late in their careers have fared.
Having scored goals at a scarcely believable rate in his home country for Santos, the Brazilian legend moved to the North American Soccer League at the age of 34.
While his spell with New York Cosmos was not quite as prolific, the switch enhanced his status as a global superstar and earned Pele stacks of cash.
It has to be concluded that this late-career transfer was a shrewd move for the three-time World Cup winner.
Okay, so Maradona's legacy was already somewhat corroded by his off-field antics and a lengthy ban after testing positive for cocaine.
But to return to Boca Juniors 13 years after departing for Barcelona was a threat to his legendary status at that club. Still, he took that risk at the age of 35 and added another chapter to his remarkable story.
Maradona's last game proved to be a Superclasico win over River Plate. A fitting finale indeed.
Angered by Ajax's decision not to offer him a contract extension at the end of the 1982-83 season, a 36-year-old Cruyff promptly signed for rivals Feyenoord.
He may have incurred the wrath of his former employers, but Cruyff's decision was a smart one as he starred alongside a young Ruud Gullit to help Feyenoord win the Eredivisie.
For a man who liked to do things his own way, this was a twilight-years move that truly paid dividends.
Taking on new challenges has never held any fear for Ronaldo, but it is clear he did not join Juventus just to spearhead their continued dominance of Serie A.
He has won honours in Portugal, England, Spain, Italy and on the international stage, but it is the Champions League title he craves in Turin. It would be his sixth.
Nobody, save perhaps for the most ardent Messi fan, would argue that Ronaldo's career will have tailed off if he does not achieve that goal, but at 35 the clock is ticking on his last great mission.
ALFREDO DI STEFANO
An Argentinian forward leaves club where he is the greatest ever player after a humiliating defeat in Europe – sound familiar?
Di Stefano was offered a place on the Real Madrid coaching staff by president Santiago Bernabeu after the 3-1 European Cup final defeat to Inter in 1964. Already suffering a strained relationship with head coach Miguel Munoz, he opted to extend his playing career at Espanyol.
Two fairly underwhelming seasons battling against relegation followed, marking an underwhelming end to a stunning career.