Lewis, who also is the team's return specialist, has sat out the Huskies' last two games with the injury. The school can apply for a medical hardship waiver through the Mid-American Conference at the end of the season.
The receiver has 3,617 all-purpose yards in his career with NIU, including eight receiving touchdowns and four kick return touchdowns.
Prior to the season, he was named to the Paul Hornung Award Watch List, which is given to versatile, high-level performers.
- Molly Geary