The summer transfer window might have been over, but that does not stop clubs for looking for potential future signings. With Barcelona's talismanic forward Lionel Messi's future up in the air, one does not see any surprises when Manchester City are linked with one of the best players in the world.

There are growing fears within the Barcelona hierarchy about the possibility of Messi, who has not signed a new contract with the club, moving on to some other club.

However, club officials remain positive about Messi signing a new deal, but the Argentine might be thinking about his future. If the player does not renew his contract, Messi could leave for free, which would be a huge loss for the Spanish giants. 

Messi, who is on City's radar, is not happy with the business conducted in the transfer window, reported The Sun. Barcelona sold one of the biggest stars, Neymar to PSG for a world record fee of £198 million.

Pep Guardiola, Lionel Messi, Manchester City, Barcelona
Pep Guardiola will be keen for a reunion with Lionel Messi at Manchester City.FRANCK FIFE/AFP/Getty Images

With such money available, Barcelona were expected to make some mega signings, but the Spanish club could only sign one star, Ousmane Dembele besides some other players.

One understands Dembele is a future star, he needs to prove himself as the French youngster will be under some pressure after being bought for £138 million. He, for sure, cannot be deemed as Neymar's replacement. Very few players in the world would be able to replace Neymar. 

Dembele might been one of their key targets, but they failed to bring one of their long-term target, Philippe Coutinho.

Barcelona gave it their best effort and made numerous offers to make the 'Little Magician' a Barca player, but Liverpool held their ground firm and did not sell the player at any cost. Barcelona, though interested, were not able to land other targets such as Angel Di Maria, Jean Seri among others.

With the departure of Neymar and failed targets, Messi mulling a move away from Barcelona makes sense as well.

Manchester City will be huge favourites if Messi does not sign a new Barcelona contract as Pep Guardiola, former Barca manager is the boss at City. Messi and Guardiola helped Barcelona win a number of titles during their time in Spain, and a reunion at City could bring favourable results for City too.