The Serbian star arrived at Stamford Bridge from Lokomotiv Moscow in a deal worth £9million back in January but has yet to start a game for the Blues and Milan are keen to sign him.
However, Milan's vice-president Adriano Galliani has spoken of his frustration after claiming Chelsea keep changing their mind.
"Ivanovic was, or better, is one of our aims," Galliani told the Italian press. "Chelsea firstly told us yes, then no. We are looking for a central defender and should we be able to find a name which suits us, we will sign him.
"It would be useless signing a player who would never play. We have a few ideas, so we will see."