Peters, a sixth-year senior, remained down after being sacked by Nebraska's Deontre Thomas on Illinois' final series of the opening quarter. He immediately went into Illinois' injury tent, and then left the field. He appeared on the sideline in the second half with his left (non-throwing) arm in a sling.
Illinois coach Bret Bielema had no immediate update on Peters' injury following the game.
Peters started 16 games for the Illini the past two seasons, completing 54% of his passes for 2,313 yards with 21 touchdowns and eight interceptions. He struggled with accuracy during a shortened season in 2020 but did not throw an interception.
"He's excited about what we're doing offensively," first-year offensive coordinator Tony Petersen told ESPN of Peters on Friday. "He's developed as a leader, which is a place he needed to develop in. We've talked about it a lot, kind of a little bit more vocal. It's not his personality but he's getting better at it every day, and I'm excited to see what he does."
Peters, a native of Avon, Indiana, was ESPN's No. 3 pocket passer and No. 60 overall player in the 2016 recruiting class. He started four games as a redshirt freshman for Michigan in 2017, but transferred after the 2018 season.