It is understood the 33-year-old sent a fax to the LaLiga giants on Tuesday asking to have his contract terminated.
Messi came through the ranks at the Nou Camp having joined the famed La Masia academy and has won 33 major trophies and a record six Ballon d’Or titles.
Reports claim the Argentina international had a clause in his contract which, if activated, would allow him to walk away from the club for free.
While the suggestion is this clause expired in May – there are claims that Messi and his team believe it should be extended to cover the prolonged season – which ran until August following the delays caused by the coronavirus pandemic.
It remains to be seen how Barcelona will respond to Messi’s request, with the club trying to rebuild following the appointment of Ronald Koeman as head coach.
Messi was part of the Barcelona side that was thrashed 8-2 by Bayern Munich in the Champions League semi-final, and speaking recently Koeman said he was looking forward to working with the forward.
“It is a pleasure to have a player like Messi in the team. His qualities will help the team to develop.” he told Barcelona’s official website.
Messi came through the ranks at the Nou Camp having joined the famed La Masia academy and has won 33 major trophies and a record six Ballon d’Or titles and it has previously seemed unthinkable that he might leave.
However, news of his potential availability is expected to be of keen interest to Europe’s top teams.
Manchester City are likely to be linked with a move for Messi, with a move to the Etihad bringing a reunion with former boss Pep Guardiola.
While coaching the Argentina forward at Barcelona, Guardiola won three La Liga titles and two Champions League trophies during a four-year spell in charge from 2008.
Guardiola mainly needs to strengthen his defence after seeing City lose their Premier League title to Liverpool, trailing the new champions by a huge 18 points, but a move for Messi may prove too hard to resist.
Neighbours Manchester United could also be interested, having already indicated this summer that they are willing to spend big through their pursuit of Jadon Sancho.
United exceeded expectations by finishing third this season but they over-relied on Bruno Fernandes for special moments of extra flair behind the strikers and Messi would certainly ease the burden on the Portuguese.
Another possible destination could be beaten Champions League finalists Paris St Germain.
The French champions have previously spent big on Messi’s former Barcelona team-mate Neymar and France international Kylian Mbappe – the two most expensive players in the world.