The Rossoneri go into the encounter in Sardinia on the back of Wednesday's 2-1 defeat to Udinese that saw them bow out of the Coppa Italia at the quarter-final stages.
The loss, Clarence Seedorf's first since taking the reigns of the club last week, was all the more painful as the Coppa remained the most realistic chance Milan had of playing in Europe next season.
"The club had given us the task of getting to the final of the Coppa Italia," Kaka said. "We are extremely disappointed because we did not want a game like this.
"There is little to say and much to do. We have to be honest, we are very far away from the qualifying positions for Europe.
"The Italian cup was much closer and it was the surest way for us. We have to all give our contribution to the team.
"We still have the Champions League last-16 tie against Atletico Madrid to look forward to and I'm sure Clarence will tell us what to do and provide us with the motivation to pick up as many points as possible in Serie A."
Milan beat Hellas Verona 1-0 last weekend to climb to 11th in Serie A, seven points behind Inter Milan who hold the last European qualifying spot.
Opponents Cagliari will seek home comfort after their winless run on the road continued with last weekend's 1-0 defeat at Atalanta.
The result followed their 4-1 loss against Juventus and dropped Cagliari to 14th place, four points clear of the drop zone.
"We were unlucky to concede a goal considering Atalanta only had one chance during the game," Cagliari coach Diego Lopez said. "We must react and play with confidence against Milan."
Cagliari have lost just twice at the Sant' Elia stadium this season but go into Sunday's match looking for their first victory since December 8.
Cagliari are without the services of Mauricio Pinilla, who serves a one-match ban. Marco Sau, who is Cagliari's top scorer with four goals this season, will lead the Rossoblu in attack.
Milan will be without injured defenders Cristian Zapata and Matias Silvestre but welcome back midfielder Sulley Muntari from suspension.