Nebraska’s backfield has taken a major hit.

On Friday, Huskers head coach Scott Frost announced that running back Tre Bryant is retiring from football, citing knee injuries for the decision. Bryant was entering his junior season with the team.

According to Sam McKewon of the Omaha World-Herald, Frost said that Bryant’s knees “won’t hold up” and that he’s having trouble sleeping at night.

Bryant played in just two games for Nebraska last season, but was explosive in those two contests, racking up 299 yards and two touchdowns. He suffered a season-ending injury and missed the remainder of the 2017 campaign.

The running back also missed all of spring practice but was expected to be fully recovered for fall camp.

In two seasons in Lincoln, Bryant totaled 471 yards and three touchdowns. He also hauled in eight catches for 56 yards and a touchdown.

The Huskers still have Devine Ozigbo and Mikale Wilbon in the backfield, but Bryant was a player with huge playmaking ability.

Nebraska opens the season Sept. 1 against Akron.