Now, as per the latest update provided by Don Balon, three clubs are ready to secure the signing of Roberto by meeting his release clause of 40 million euros ($47million) and Manchester United are one of them.
Don Balon reports that United are one of three clubs interested in snapping up the 25-year-old Spain global.
The player, who can also operate as a defensive-midfielder and right winger, impressed last season under former Barcelona manager Luis Enrique, where he scored the famous goal that stunned French side Paris Saint-Germain in the Champions League last season.
However, it has also been suggested that Chelsea and AS Monaco may be in the hunt for Roberto, who is contracted to Barca until 2019.
Barca have been strongly linked with the likes of PSG's Marco Verratti, Borussia Dortmund's Ousmane Dembele, Liverpool star Philippe Coutinho and Guangzhou Evergrande midfielder Paulinho.
Sergi Roberto has been deployed as a right full-back for last two seasons with the Barcelona squad possessing excellent midfield talent such as Andres Iniesta, Sergio Busquets and Ivan Rakitic.
Reports in his homeland earlier this month claimed United boss Jose Mourinho had already made an approach for him by contacting him directly.
Mourinho has already acquired Nemanja Matic from Chelsea but is on the lookout for another player.