The talismanic Argentine is widely regarded as one of the greatest footballers of all time and has spent his entire professional career with Barcelona, inspiring the club to 33 trophies.
Messi has scored an incredible 634 goals - and created 285 more - in 731 appearances for the Catalan giants, winning a record six Ballons d'Or during his time at the club.
However, a chaotic season on and off the pitch has led to him asking to leave for the very first time, prompting widespread speculation over where he could end up next.
Much could depend on a potential legal battle over his contract, with Barcelona claiming that a clause stipulating that he could leave on a free transfer expired in June but Messi arguing that it should be extended in line with the increased length of the season.
The outcome of that could be the difference between Messi leaving on a free transfer and Barcelona being able to demand £632m for him, which is the release clause in his current deal.
Even if he is available for free, only a select few clubs in world football could afford his mammoth wages, and here Sports Mole looks at where the legendary number 10 could end up.
Manchester City are one of the few teams who could possibly afford to pay Messi's wages, although they have already narrowly escaped a Financial Fair Play punishment.
The most attractive aspect of moving to Man City could well be Pep Guardiola, under whom Messi played the best football of his career for Barcelona.
Man City also boast Messi's compatriot and good friend Sergio Aguero among their ranks, although the futures of both Guardiola and Aguero remain uncertain beyond the end of next season.
City are expected to strengthen this summer having surrendered their Premier League title and again fallen short in the Champions League last season, the latter of which the owners are more desperate to win than any other trophy.
That desire tallies up neatly with Messi's priority of challenging for Europe although, having already signed Ferran Torres and Nathan Ake this summer, even Man City could struggle to afford the Argentine.
The world's other mega-rich team for whom money is a far smaller hurdle than it is for anyone else, PSG have been linked with a sensational move for Messi.
Manager Thomas Tuchel laughed off such suggestions after his side's defeat in the Champions League final, but also admitted that any manager would welcome Messi.
PSG's owners do not exactly lack ambition and the idea of signing Messi from Barcelona, with whom they have endured a spiky relationship, on a free transfer would be of great interest to them if it is financially possible.
Like Man City, PSG's owners view the Champions League as the holy grail and, having reached the final this year, appear closer to achieving that goal than the Citizens, which would be appealing for Messi.
Speculation linking Inter Milan with an interest in Messi refuses to go away, and has been around for longer than a Messi exit from Barca seemed feasible.
The Italian giants appear to be on their way back towards challenging for silverware following a spell in the doldrums, finishing second in Serie A and as runners-up in the Europa League last season.
However, Messi wants more Champions League glory to add to the four titles he has already won in that competition, and Inter appear to be some way off the very best Europe have to offer at the moment.
Money would also be more of an issue for them than PSG and Man City, although they could look to raise funds by offloading Barcelona target Lautaro Martinez in the opposite direction.
A move to Italy would also see him renew his rivalry with Cristiano Ronaldo, who joined Juventus from Real Madrid two years ago.
The most unlikely move on this list, but one there has nonetheless been growing speculation about.
Should those go through then Chelsea will have already spent more money than ever before in a single transfer window - including a club-record £90m deal for Havertz alone - and it therefore seems unlikely that they would also be able to afford Messi, even on a free.
The Blues do have money in reserve, though, having failed to sign any players last summer or in January while selling a number of people including Eden Hazard, while further fund-raising sales are expected this summer.
Chelsea finished 33 points adrift of Premier League champions Liverpool last season, though, and only narrowly qualified for the Champions League, meaning that the prospect of winning immediate silverware with them appears less likely than at other options.