The former Netherlands international was appointed as Rossoneri coach in January after Massimiliano Allegri's sacking, but he was unable to sufficiently inspire the club up the Serie A table as they eventually finished eighth.
Milan consequently removed the former midfielder from his role, paving the way for Filippo Inzaghi to come in.
Italian football clubs typically place departed coaches on 'gardening leave' rather than terminating their contracts, meaning Seedorf would need to be paid until June 2016 - when his deal was due to expire.
The club and Seedorf are in talks in an attempt to resolve the situation, but Treu - a member of the former Netherlands international's legal team - expects the dispute to end up in court.
"We hope for an amicable solution and [one] that satisfies both parties, but the last meeting did not go very well," he is quoted as saying by Gazzetta Dello Sport.
"As things stand, there is a high chance we will end up in court."
Milan top Serie A after winning each of their opening two games of the season under new boss Inzaghi.
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