The 23-year-old has made just seven starting appearances since his move from Atalanta in the summer.
Bigon told Sky Sports: "No, he is not leaving. Luca is important for our squad and will certainly give the team a big hand during the rest of the season.
"Anyway he's an important investment and Luca wants to earn himself a role as a protagonist here in Napoli. I am convinced he'll stay."