The Turin giants were crowned Serie A champions in the penultimate week of the campaign and then celebrated in front of their home fans two days ago after beating Atalanta 3-1 to cap an unbeaten season.
"This game is very important for us just as it is for Napoli," said Juventus defender Leonardo Bonucci said.
"It will be an important test for us to see if winning the scudetto was enough for us or if we still have some appetite left."
The match will be the last in the Juventus uniform for captain Alessandro Del Piero.
The 37-year-old forward hopes to end his 20-year Juve career by lifting his second Coppa Italia.
"There are incredible moments that fill you up for ever," Del Piero said. "Like a scudetto victory or lifting a Coppa Italia.
"We celebrated on Sunday but now our focus is in Sunday's final.
"We want to cap off what has been a great season with a beautiful victory in Rome."