La Viola confirmed the Italian international had suffered a "sprain" to his right knee, the joint in which he has twice damaged cruciate ligaments. He was replaced in the 71st minute of the match.
A club statement read: "Fiorentina announce that following a challenge from Livorno player Leandro Rinaudo, Giuseppe Rossi suffered a sprain to the knee that had already been operated on. Tomorrow more tests will be performed."
Rossi missed almost two seasons after two cruciate ligament injuries while at former club Villarreal, but has recovered to lead the Serie A scoring charts this season with 14 goals. He has also returned to the Italy squad.