Materazzi went off midway through the second half after being caught in the face by Ibrahimovic's knee in a full-blooded challenge yesterday.
However, Inter coach Rafael Benitez insisted there was nothing to worry about.
"He was knocked out but it doesn't seem to serious," said the Spaniard, who refused to blame Ibrahimovic.
"It's a bad challenge but it wasn't his intention so I can't say anything"Ibrahimovic scored the only goal of the game as AC Milan went back to the top of Serie A, with Inter dropping to fifth, six points behind.
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