Messi shocked the football world last week by submitting a formal transfer request at Camp Nou, which saw him outline his desire to activate the release clause in his current contract, which expires in 2021.
A number of possible next destinations have been mooted for the 33-year-old in the wake of the news, including Paris Saint-Germain and Juventus, but Goal learned that City boss Guardiola had been in contact with Messi prior to him dropping his transfer bombshell.
Messi decided to not to show up for pre-season medical checks at Barcelona's academy base over the weekend, and will not be reporting to any further training sessions in order to distance himself from first-team affairs.
Jorge Messi, who serves as his son's main legal representative, touched down at El Prat Airport in Barcelona on Wednesday amid the intense speculation surrounding the Argentine's future.
The 62-year-old agent told El Chiringuito of Messi's current situation upon his arrival in Catalunya: "A future at Barcelona? It is difficult. It would be difficult to stay."
Quizzed on City's interest in the Blaugrana talisman, Jorge responded: "I haven't talked with Pep. There is nothing yet with City."
Messi has spent his entire career to date at Camp Nou, where he has managed to establish himself among the greatest players in the history of the game.
The Argentina international currently stands as Barca's all-time top goalscorer with a staggering 634 goals from 731 appearances, and he has also contributed 285 assists to the club's cause.
Messi has picked up 33 major honours in total during his time at the club, including four Champions Leagues and 10 La Liga titles, but was part of a squad that failed to win a single piece of silverware in 2019-20.
Quique Setien was relieved of his managerial duties in the days after that result, with ex-Netherlands boss Ronald Koeman drafted in as his replacement.
Koeman has expressed his desire to see Messi remain at Camp Nou, but a club legend has already made up his mind to move on, regardless of what changes are made to the squad or in the board room.
Barca presidential candidate Victor Font has admitted there is little chance of convincing a prized asset to stay put, telling Sky Sports: "Until it's over there is always hope.
"It doesn't seem likely, though, and therefore if that's the case, the focus should be on making the transition as smooth as possible."