Many Juve identities say management shouldn't rush to upgrade the midfielder's contract, given his current deal runs to 2029.
But Spalletti said ahead of this weekend's clash with Fiorentina: "It's not up to me to decide on the renewal.
"For me, Yildiz is the one who breaks the rules. He's the one who makes the last shot in the night. I like to imagine him like that, and talking to Yildiz means talking to the team.
"He has the attitude of a team leader. For me, he's everything."
Spalletti added, "Being a Juventus player doesn't mean being arrogant, but knowing how to handle this pressure."