Christian Vieri has taken aim at AC Milan's owners.

Previewing the Champions League quarterfinal between Milan and Napoli, Vieri highlighted the lack of investment made in the Rossoneri squad by RedBird Capital and previous owners Elliott Management.

He told Il Corriere della Sera of Napoli, "It's a perfect machine, I've never seen a club show up so strong after a real technical revolution.

"(Luciano) Spalletti's teams play football well, it's always been like this. His imprint is very recognisable, he has gained total experience, and he knows how to read every detail perfectly in the various moments of the match and of the season.

"He will have to pay close attention to Milan, but it wouldn't be a surprise if they win the Champions League. The Rossoneri, on the other hand, have two phenomenal players like (Paolo) Maldini and (Ricky) Massari, but the ownership must come out into the open. Stop hiding.

"Milan doesn't spend anything and the managers work wonders with (Stefano) Pioli. Now the objectives need to be clarified."