Barcelona vice-president Josep Maria Bartomeu has said that the club have started negotiations with Udinese for Chile forward Alexis Sanchez.
According to the Sun, Gill flew out to meet with Udinese owner Gino Pozzo in Barcelona, where he lives, in a bid to thrash out a deal for a player who is also being tracked by Barcelona and Inter Milan.
There are conflicting reports around how much it will cost to secure the services of the Chile international, with a figure between £35 million and £44 million in the press. Man City are thought to be prepared to pay no more than £27 million, which may mean Udinese have to reach a compromise with one of the player's suitors.
If United do make a serious move for Sanchez it could suggest that their interest in Aston Villa's Ashley Young has cooled as a summer of transfer tug of war continues in the Premier League. And Sanchez's arrival would also place question marks over the future of Nani, who could be sold to help finance the Red Devils' summer spending.
After Pozzo stated on Tuesday that City were favourites, due to the spending power of clubs in the Premier League, the 22-year-old's agent, Fernando Felicevich, said: "An agreement with City? Sanchez's future is still very much wide open.
"We are working on it and, after meetings with City, we have other new appointments."