Nelson entered his plea Wednesday. The 21-year-old collegiate athlete had been charged with two felony assault charges that carried a maximum 20 years in prison. The misdemeanor charge carries a possible 90 days in jail.
The Star Tribune (http://strib.mn/1Cbu0N5 ) reports that Nelson told the judge he didn't know Isaac Kolstad, a former Minnesota State linebacker, but acknowledged they fought last May in Mankato.
A medical expert previously said Nelson's kick to Kolstad's head probably didn't cause his severe injuries and that it was likely the result of a punch by another defendant and his head hitting the pavement.
Sentencing is scheduled Feb. 25.
Information from: Star Tribune, http://www.startribune.com