Illinois’ hopes for an upset bid just dwindled a little more.

Saturday morning, Jeremy Werner of the Illini Inquirer tweeted that starting running back Ra’Von Bonner is ruled out against Wisconsin due to a concussion. Bonner, a freshman, was starting in place of another injured back Mike Epstein.

Kendrick Foster will get the start for the Illini.

Bonner has rushed for 202 yards and four touchdowns in six games this season. Last week against Minnesota, the freshman accounted for 57 yards and a score on 18 carries.

Foster has played in all seven games for Illinois this year but has only taken carries in four games. He’s totaled just 31 yards on 13 touches. Last fall, Foster was the team’s leading rusher with 720 yards and seven touchdowns.

Illinois’ offense has already been hampered by injuries and has enough trouble moving the football as is. This is another huge blow for Lovie Smith and Co., especially this week against No. 5 Wisconsin, which owns one of the best defenses in college football.

Wisconsin-Illinois kicks off at noon ET and will air on ESPN.