The Swedish star conceded that he was left injured from the fight with the American defender and stated he is a regular target of racial chants in Italy
The pair made headlines in November of 2010, when the United States international started a fight with Ibrahimovic in a practice session at Milanello after he suffered a nasty challenge from the Sweden international.
It is reported that Onyewu, currently on the books of Sporting Lisbon, and Ibrahimovic exchanged blows before being separated by team-mates.
At the time, Milan vice-president Adriano Galliani played down the incident, which he described as a 'lively fight', but Ibrahimovic, who is a black belt in taekwondo, admitted it was not a normal brawl between players.
"Onyewu and I almost killed each other," said Ibrahimovic in his autobiography, titled 'I Am Zlatan Ibrahiovic', according to the Swedish press.
The former Inter star claimed that he suffered a broken rib as a result of the fight.
The 30-year-old also said that racial chants are normal in Serie A matches and that he is used to being called a "gipsey" by fans.
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