The Partenopei have been highly active in the transfer market this summer, with the likes of Gonzalo Higuain, Pepe Reina and Raul Albiol arriving on the back of Edinson Cavani's €63 million move to Paris Saint-Germain.
And Astori looked set to become Rafa Benitez's latest addition this week, but Cellino revealed the 26-year-old will now not be making the move to last season's Serie A runners-up.
“I am a friend of Aurelio De Laurentiis and we did have a deal for Astori,” Cellino told Radio Kiss Kiss.
“At that stage Astori asked me if he should still consider himself a Cagliari player. I said yes, assuring him he wouldn’t be sold.”
Astori began his career with AC Milan before joining Cagliari in 2008, where he has gone on to become a firm fixture in the first team, while winning five caps for Italy. His current deal with the Rossoblu runs until June 2015.