Cosmi was fired after a 4-0 defeat by Sicilian rivals Catania.
But Rossi, who was fired after owner Maurizio Zamperini accused him of ruining the club, is back as Serie A rules forbid more than two managers taking charge of one team during a season.
Cosmi was fired after a 4-0 defeat by Sicilian rivals Catania.
But Rossi, who was fired after owner Maurizio Zamperini accused him of ruining the club, is back as Serie A rules forbid more than two managers taking charge of one team during a season.
