Milan suffered a 2-1 defeat to Fiorentina on Monday that increased the pressure on the under-fire Inzaghi.
Donadoni, who won six Serie A titles and three European Cups in two stints with Milan as a player, led Parma to sixth in the league last season but looks powerless to prevent the cash-strapped club from succumbing to relegation this term.
And he told Gazzetta TV: "If Milan calls me, I don't think it's going to be hard to answer.
"The last few games could have changed things for Milan, but unfortunately they did not go well."
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