The Premier League champions are not only interested in signing a number of Blaugrana players, but have attempted to lure away employees at other levels, too
The Premier League champions already have former Barca directors such as Txiki Begiristain and Ferran Soriano under contract, and they are evidently keen to add to their Barcelona contingent.
"Manchester City have indeed launched an offensive to lure a number of people away from Barcelona," Rosell told RAC1.
"We're talking about people at all levels of the Barca structure, not just players. Their attempts have been unsuccessful, though, as our employees are happy here.
"There have been contacts, but we have a fantastic group of people and nobody wants to go."
Rosell then went on to urge Manchester City CEO Soriano to act professionally and not to use the information he has about Barcelona to the Citizens' benefit.
"I had hoped that he would not use the information he gathered about Barcelona during his time here to help another club become bigger, but he seems to disagree with me.
"I would like it if the relationship between both clubs was a bit better and more transparent."
Goal.com exclusively revealed last year that City are keen to sign Barcelona wonderkid Jean Marie Dongou, while they have also shown an interest in adding Gerard Deulofeu and Sergi Roberto to their ranks.