Genoa president Enrico Preziosi says he had no choice but to sack Gigi del Neri.
Preziosi is worried with their current position in the relegation zone.
"When the Coach loses 10 games out of 13, there's not a lot you can do," he told Sky Sport Italia. "This does not mean I blame the Coach, but we cannot afford to stand still and do nothing.
"I have a lot of affection for Del Neri, but I feel I have made the right decision.
"Ballardini has already done well with Genoa in the past, and I wish him good luck with the rest of the season.
"A team like ours with these sorts of players should not be in this problem."