There had been reports of negotiations having broken off this week.
But Bolzan says the move is imminent.
"The topic is on its way to being finished," Bolzan told reporters after Grêmio's match on Wednesday. "The documents are not signed yet, but the transfer is reaching the final phase.
"I think it will be over by tomorrow or the day after tomorrow. "Some things still depend on legal issues. It still requires some care.
"It is heading towards a final situation tomorrow, I believe."