It has been reported in Italy and England that the Black Cats have turned their attentions to the 28-year-old attacking midfielder and submitted a bid of €10million (£8.6million).
However, his agent does not believe that Juventus are looking to sell.
"Myself and my partner have not called anyone, and also [Juventus director general Giuseppe] Marotta has made it very clear on the future of Giaccherini," he told Furio Valcareggi IlSussidiario.net.
"And he gets on well with Antonio Conte, who is a great coach and he has no intention of selling him - he is not for sale."
Asked if the player was looking for a move, he added: "Absolutely not, he is fine at Juventus.
"He has the confidence of everyone and still wants to win so much. I believe Juventus are in a strong shape to win a third consecutive title."