The Swiss club started talks this week and hope to provide the Juventus legend with the next stage of his playing career.
"The sensations are positive," Sion director general Marco Degennaro told Sky Sport Italia television.
"We spoke to Del Piero's entourage and explained out projects. We proposed a contract to Del Piero. How long was the deal for? We didn't get into these details but, after Gattuso, we want to sign another champion."