Arriving at Illinois as a highly touted recruit, Wilson did not live up to the expectations in his first two years. In the season opener of his junior year, he suffered a herniated disc in his neck, which forced him to miss the remainder of the 2009 season. He was granted a medical hardship waiver and retained a year of eligibility. By 2010, he evolved into one of the best linebackers in the Big Ten Conference, ranking second in the conference in tackles (9.1 tackles per game) midway through the season.
Wilson announced his decision to forgo his senior season, and enter the 2011 NFL Draft, on January 10, 2011.