The 27-year-old, who has one cap for Italy, is set to put pen to paper with the Turin giants on Friday at the latest after catching the eye in an impressive 2013-14 campaign.
Marotta revealed at a press conference on Thursday: "Romulo? Between today and tomorrow will be a Juventus player, his agent will be here tomorrow in Turin to close."
Brazil-born Romulo's representative, Alex Firminio, also confirmed that the former Fiorentina man is on his way to Juve.
"It is virtually a done deal with Juventus," Alex Firminio told Calcio News. "We are delighted and want to thank everyone at Verona for believing in him.
"Tomorrow I will arrive in Italy and we will sign. I’ve spoken to Romulo and he is really happy to have been given an opportunity like this at Juve."
Marotta added that Juve are monitoring Paris Saint-Germain's teenage midfielder Adrien Rabiot, but is unsure if they will be able to lure him to Serie A.
"Rabiot? It (is) a very interesting player, but is owned by PSG. It is still a player who we know very well that our observers have seen repeatedly. For the moment we cannot help but watch."