AC Milan have lost captain Massimo Ambrosini and goalkeeper Christian Abbiati to injury.
Both players were injured during Sunday's 1-0 defeat at Juventus, with Abbiati replaced by Marco Amelia after just 15 minutes and midfielder Ambrosini substituted at the break.
A statement on the club's official website read: "AC Milan would like to communicate that Massimo Ambrosini sprained his right ankle during the match against Juventus and has suffered some ligament damage.
"Christian Abbiati, meanwhile, has strained his right calf. Both will have a better idea of how long their recovery time will be further into the week."
They join Nigel de Jong on the injury list, with the trio all ruled out of Sunday's match at home to Catania. Cristian Zapata is also suspended for the match.
Information from the Press Association was used in this report