Wednesday's home defeat to the Greeks was painless as Inter qualified for the Champions League last 16 courtesy of results elsewhere but it proved that the inconsistency the Italian champions have shown this season was not buried by last weekend's well-earned 1-0 win over Juventus, which sent them three points clear.
"After this result we have to present ourselves at our stadium against Napoli on Sunday with the right drive and with anger to play a different match from the one we deservedly lost to Panathinaikos," Mourinho was quoted as saying on the club's website (www.inter.it).
"Kaka is irreplaceable even when he isn't playing at his best," Ancelotti told reporters ahead of Milan's UEFA Cup tie at Portsmouth on Thursday.
Dutch midfielder Clarence Seedorf is tipped to move forward to take Kaka's place alongside the in-form Ronaldinho in support of a lone striker, who is likely to be Alexandre Pato.
Milan's Kakha Kaladze risks a suspension after being charged by the Italian Football Federation for saying Stefano Farina was a poor referee following Sunday's 2-2 draw at Torino.
Last season's runners-up AS Roma are seeking to continue their recovery from a miserable start with a home win over Fiorentina on Sunday.
