Fassi has backed up Martinez's comments and hinted that there is already an agreement in place for the three-time Mexican international to make the move to European football.
"There have been approaches [from Manchester United]. There will be time to focus on the future of Hirving Lozano," Fassi told Record MX.
"Pachuca several years it has a structure of great relationship with many teams of England, in Portugal in Spain, in France, in Italy and in Germany. There are some agreements that allow the player to go to Europe in the future."
Lozano has scored 33 goals in 122 appearances for his Mexican club.