The 26-year-old, who bagged 15 Serie A goals last season, is reportedly keen on a move back to newly-crowned Italian champions Juventus.
Andrea D'Amico said that the competition at the Etihad Stadium means that his client would prefer a move to the Bianconeri.
"If Juventus and Parma can reach an agreement then the issue will be resolved," D'Amico told Tele Radio Stereo. "Sebastian has had a great season, thanks to the excellent work of Roberto Donadoni.
"The coach called him the best Italian talent. We expect that the two clubs will speak. I doubt that the move to Manchester City is possible, especially as they have so many players in attack already like Sergio Aguero and Edin Dzeko."
Giovinco, who has seven caps for Italy, made his loan move from Juventus permanent last year.