Busquets, 24, has a £121m release clause with the Catalan giants while some reports suggest that the Citizens are also eyeing former Arsenal captain Cesc Fabregas. The Barca forward has been in-and-out of Tito Vilanova's 4-3-3 system.
De Rossi, 29, was linked with a move to Eastlands during the summer transfer window, but a deal failed to go through after Roma's £630m asking price. However, according to reports, De Rossi is currently unhappy with new Roma manager Zdenek Zeman, raising doubts over his future with club.
Despite signing Javi Garcia, Jack Rodwell and Scott Sinclair, boss Roberto Mancini is willing to link Busquets with midfield sensation Yaya Toure.
Meanwhile, City deny making bids for the Barcelona duo claiming they have made no contact with the Catalans and are not interested in submitting bids for the World Cup winning duo.
"There's no basis to these claims and the club has neither made nor is it planning to make an offer for these players," a Manchester City statement said.
Busquets has been with Barca for his entire career making over 200 appearances for the La Liga giants while former Gunner Fabregas joined Barcelona a year ago after spending eight seasons with Arsenal.