Thiago Silva was sold by Milan in August.
"It's not easy to judge from the outside, but I've never seen a Milan side like this," he told the Gazzetta dello Sport.
"It is certainly not Milan-like to lose six of their first 12 League games. I hope they can pick themselves up."
The Brazilian was one of the many big name players to leave the Diavolo this summer, but he's still a fan.
"I'll always be a supporter of the Rossoneri because I was really happy at that club."