Nwangwu left Saturday's preseason game against the Broncos with a knee injury, Courtney Cronin of ESPN.com reports.
The rookie sixth-round pick likely hurt his knee on an 18-yard return of the opening kickoff, considering he left the contest before taking a touch on offense. Nwangwu might've had a busy evening if not for the injury, with Dalvin Cook and Alexander Mattison both healthy scratches for Saturday's exhibition. Instead, the Vikings leaned on undrafted rookie A.J. Rose and 28-year-old Ameer Abdullah to handle backfield snaps.