The Brazilian joined Inter on Wednesday, with the Italian giants paying Nice 20million euros for his services.
Dalbert only joined the French outfit last summer and he made 33 appearances last season to help his side finish third in the Ligue 1 table.
He will now be hoping to make his debut on August 20 when Inter take on Fiorentina at home but Spalletti insists he needs to develop his game.
Spalletti told Sky Italia: "He’s an important prospect.
"He has to learn some things for our football though, and the margins are thin. It’ll take commitment, we’ve already said that and he’ll do it."