Barca captain Messi, whose contract runs until June 2021, is said to have a clause in his deal that allows him to leave on a free transfer at the end of the campaign.
It was required to be activated before the end of May but, due to the season being extended into August amid the coronavirus pandemic, Argentine outlet TyC Sports claims the six-time Ballon d'Or winner has told the Catalan giants he still intends to make use of it.
Messi last week held talks with head coach Ronald Koeman, who replaced Quique Setien at the helm after Barca was humiliated 8-2 by Bayern Munich in the Champions League quarter-finals.
The 33-year-old reportedly told Koeman he was leaning towards a departure from Camp Nou and it appears he has committed to that decision after close friend Luis Suarez was apparently told they were no longer required at the club.
Seemingly responding to the news, former Barca skipper Carles Puyol tweeted: "Respect and admiration, Leo. All my support, friend."
Having spent his entire professional career with Barca, Messi has been linked with a return to Argentina to play for boyhood club Newell's Old Boys in his hometown of Rosario.
A reunion with former Barca boss Pep Guardiola at Manchester City has also been mooted, while Inter have been long-term admirers. According to TyC Sports, a move to MLS could also be on the cards.
Messi is Barca's all-time leading scorer with 634 goals and 276 assists in 731 appearances in all competitions for the club.
The Argentina international made his first-team debut as a 17-year-old in 2004 and has won 34 trophies at Camp Nou.
He had looked set to add to that haul with Barca sitting two points clear at the top of LaLiga when the season was suspended in March due to COVID-19.
However, it let its advantage slip and ended up finishing five points adrift of eventual champions Real Madrid.
Sporting director Eric Abidal was let go in the wake of that Champions League exit, while presidential elections have been brought forward to March as a turbulent period for the club continues.