The player has been accused of punching and badly injuring a waiter in a bar in the early hours on Saturday. Mutu, whose nine-month drugs ban ends on Friday, has made no comment.
"I saw Adrian this morning briefly and it's better I don't tell you what I said to him because we are before the watershed. It's a serious thing, we will wait for the investigation," Fiorentina director Andrea Della Valle said in a club statement.
"We've got to wait because we don't know exactly what happened. We will act calmly. It's not the first time this sort of thing has happened but it's never been so serious."
Fiorentina have always previously stuck by the striker but Della Valle's statement suggested strong action could follow if he is found guilty of the assault.
