The five-time World Player of the Year has never indicated his desire to leave the Camp Nou after 15 successful years at the club.
It is being reported that City have no plans to try to lure the Argentina forward to the Premier League, but if he ever decides to leave, City will be at the head of the queue.
Messi thrived when Guardiola was in charge at Barcelona when the club won three La Liga titles and two Champions Leagues and the club that would be a way of attracting him to the Etihad.
Messi's contract at Barca runs until 2018 and the likelihood is that he will be offered another extension before it expires.
The imminent arrival of manager Guardiola has already seen an immediate impact in the calibre of players they can hope to attract since the club announced on Feb. 1 that he would be taking change.
And it would be a huge statement if City were able to sign arguably the best player of the world.
City have have been linked with summer moves for midfielders Ilkay Gundogan from Borussia Dortmund and Real Madrid's Toni Kroos and defenders Aymeric Laporte, from Athletic Bilbao and Everton's John Stones.
On Monday, reports said the club were targeting four to five major signings this summer.