After failing to get a move away last month, the defender has seen youngster Diogo Dalot jump ahead of him in the fullback pecking order at Old Trafford.
Tuttosport says the situation has only hardened Darmian's resolve to leave United.
Over the summer, Darmian admitted: "My agent knows what I want. Juve, Inter or Napoli?
“It's not my role to answer that question, I'll move for the best solution and I'd consider all possibilities.
“One year ago, I was close to return to Italy but Mourinho and the club didn't want to sell me so nothing happened. An important proof of esteem, but I'm now looking for continuity."