His contract expires next summer and he is in two minds about where he sees his future, according to The Sun.
Messi confided in his Argentina team-mates during the international break over what he should do.
He has been negotiating a new contract with Barcelona for 18 months and the new deal is worth £500,000-a-week and comes with a record-breaking £80m signing bonus.
But Manchester City are willing to pay him a £90m bonus to go to the Etihad and could offer a world-record transfer fee of £357m.
City officials have met with his representatives on a number of occasions and could look to sign him for a fee in January, or wait until he is a free agent in June.
Messi is not convinced about Barca’s ambition following the sale of Neymar to PSG and the appointment of Ernesto Valverde as manager.
He has also become disillusioned by the political unrest surrounding the Catalonian independence referendum.
Barca chiefs hope he will put pen to paper on the new deal now that Argentina’s World Cup place is confirmed.
Messi scored a stunning hat-trick in a 3-1 win over Ecuador earlier this week to send them to Russia.
If City do sign Barca’s record goalscorer then he’ll be reunited with Pep Guardiola who managed him for four years at the Nou Camp, where they won three league titles and two Champions Leagues together.
Earlier this week City striker Sergio Aguero said that he would love to join forces with his international team-mate in the Premier League.
La Liga leaders Barcelona return to league action tomorrow with a trip to Atletico Madrid, before hosting Olympiakos in the Champions League on Wednesday.
