Negotiations have been reported throughout the day but a deal is yet to be concluded.
“Negotiations continue, tomorrow you will know more,” Marotta told reporters.
“Tomorrow [Tuesday] we will tell you everything, negotiations can go on and on and tomorrow we will see how the situation evolves.
“Football is a dynamic market.”
The proposed transfer has been filled with unusual twists and it has been reported the Nerazzurri pulled out of the deal at the last minute after fans protested about the move.
In addition, it is believed Guarin refused to leave the Bianconeri’s offices in order to force a transfer to the Serie A champions.
Marotta’s comments, however, could indicate the transfer is almost finalised with reports stating Inter will receive €2 million plus the Montenegrin for the services of Guarin.
Vucinic has scored two goals in eight appearances for Juventus this season, Guarin has scored 3 in 19 appearances for Inter.