Rossi was fired for slapping Adem Ljajic in the face after the Serbian forward protested his first-half substitution Wednesday during a 2-2 draw with Novara. The coach then had to be pulled away as it appeared he was lining up a punch.
Former Italy coach Arrigo Sacchi told Tgcom24 on Thursday that the act was "deplorable, but it's the consequence of the environment. The football system lives on excess and when everything is excessive reactions become that way, too."
The 59-year-old Guerini has formerly coached Fiorentina's youth squad.