The 31-year-old midfielder was eager to keep his focus on the field, and said the club would not become entangled in another war of words with Madrid.
[Jose] Mourinho is a controversial coach, he always has been and he uses that as his weapon. But I would like to talk more about football."It saddens me to talk about things that have nothing to do with this great sport of football," he continued referring to the recent controversy which overshadowed the first-leg last week
"We must not get into a war of words with Mourinho. Like Pep [Guardiola] says, Mourinho always wins the war of words, we need to speak on the field."
Xavi was asked what he thought about Real Madrid's complaint to Uefa, and subsequent rejection from the governing body, regarding alleged unsporting behaviour from Barcelona players.
"I think it's lamentable because these complaints do not lead anywhere, and Uefa have obviously rejected them," he added.
"Barcelona have always shown exemplary conduct in their matches."
He then accused Madrid of failing to play according to the rules.
"Madrid's play is not football. People want to see attractive and offensive football, not a team closed up behind, and the fans do not want to see a dry football pitch with long grass.
"We have to leave these things behind though and play our own football."
Barca hold a 2-0 advantage ahead of the second-leg at Camp Nou on Tuesday.