Juventus have told Zenit St Petersburg that Italian international Leonardo Bonucci is not for sale.
Reports this week suggested that the Russian club had made an offer, but it has been turned down by the Old Lady.
"It's true that Zenit made an offer for him, but we are counting on him," Juventus director general Beppe Marotta noted.
"Leonardo is young and last season was his first experience at a big club. We'll continue with him in the new season.
"We don't want to satisfy the request of the Russian club."
The centre-back joined the Bianconeri a year ago in a €15.5m deal following his impressive season at Bari.
Meanwhile, Marotta added that Juventus' busy summer of spending was not yet over amidst reports that they, like Milan, were plotting a Mr X swoop.
"There is no Mr X for us," he added. "We already know what we want, we just don't want to divulge their names. You can't sell the fur of a bear before you have it in your possession.
"We have certain needs, but we have to go about it in an ethical way by not overpaying for players.
"Boss Antonio Conte wants a competitive and consistent squad. We will try to please him."
It's understood that the Turin giants will sign a new centre-back and a left-sided midfielder before the window closes.
"Juventus want to get back to winning," added the official. "The quality of the team has notably been improved and that is a good omen."