Fiorentina will be without midfielder Marco Donadel for the next two months, but the club have signed Zdravko Kuzmanovic.
Donadel damaged a leg last Friday and tests during the week confirmed he has suffered a torn muscle.
"It's a bad injury," said Viola doctor Paolo Manetti. "Recovery periods can differ, but it is usual that it is necessary to be out for six to eight weeks."
The Viola were able to bring in a midfield replacement on deadline day in the guise of Kuzmanovic.
Fiorentina beat off competition from Palermo to snap up the player from Basel.
Kuzmanovic has signed a deal which ties him to the club until the summer of 2011.