Much has been said about the decisions of match officials in recent Barcelona matches as the Catalans disputed the dismissals for Thiago Alcantara against Mallorca and Gerard Pique versus Sporting Gijon.
Mourinho has also been vocal about refereeing calls going Barca's way in Europe in recent seasons, and he wants the talking point of Wednesday's clash to be focused only on the football.
"I hope it is a beautiful game and at the end of it we are not talking about the referee," Mourinho said to reporters.
Meanwhile, Madrid playmaker Kaka is confident that AC Milan will know what to do to get a positive result against Barca at San Siro.
"I will watch the game and like always, cheer for Milan. None of my former team-mates have called me so far, but Milan know how to deal with Barcelona.
"I hope that the Rossoneri will put in a good performance and get a good result."
Wednesday's match at San Siro kicks off at 20.45CET.
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