Marotta's declaration comes amid reports that both players could be on the move in the winter transfer market.
The 20-year-old Pogba is a reported target of Paris Saint-Germain and Arsenal while Italy international Pirlo, who becomes a free agent this summer, has been linked with a move to the Premier League.
"We have a strong and functional group and we don't want to sell anyone," Marotta said to Gazzetta dello Sport. "At this time there is no possibility of selling Pirlo and Pogba even if Pirlo will soon be out of contract.
"I can say, however, that we have a great rapport with the player (Pirlo) and that his contract will be extended."
Pogba, a France international, has become a crucial player for Juve since his free transfer from Manchester United in June 2012.
Pirlo joined Juve from AC Milan in 2011 and the 34-year-old has been a regular in Antonio Conte's starting XI.