Title holders Napoli currently sit seven points behind leaders Inter Milan with seven games in Serie A to play.
ADL told Calcio Napoli Club USA: "We beat Milan, so I'm really happy.
"We've had a lot of injuries: 11-12 players have been sidelined. Only now are some key players recovering, but we still have a lot of absences.
"If we hadn't had all these difficulties, we probably would have won the Scudetto again and therefore our fifth.
"But never say never, and we have next year too."
On last season's title triumph, ADL paid tribute to coach Antonio Conte: "It was an incredible experience, a thriller until the last minute, we didn't know until the very end how it would end.
"I have to say that with Conte we won because he is the king of surprises.