The 30-year-old has been tipped to join the Rossoneri on an initial loan deal for €18 million (£16m/$21m), with a purchase option at the deal's conclusion for an additional €36m (£32m/$42m).
Additionally, former Juve defender Leonardo Bonucci is nearing a move to make a return to Turin after one season with AC Milan.
Juve defender Mattia Caldara could also be heading for the San Siro in a swap deal with Bonucci.
However, Marotta claims there has not yet been a satisfactory conclusion to the discussions over Higuain.
When asked if everything was agreed over Higuain's future, he told reporters in Milan: "Not so much."
Higuain fired Juve to back-to-back domestic doubles after joining from Napoli in 2016.
However, the €112m arrival of Cristiano Ronaldo appears to have prompted him to seek a new challenge elsewhere.