Ferguson broke down during Saturday's 0-0 draw with Monza and it means he is also out of Scotland's Euros squad.
Bologna announced today: "The tests to which Lewis Ferguson underwent following the sprained trauma to his right knee highlighted the injury to the cruciate ligament.
Advertisement
Advertisement
"The player will undergo surgery after which the recovery time will be defined."
Ferguson has been a key player for coach Thiago Motta this season.