Kendial Lawrence out at least 4 weeks
Missouri coach Gary Pinkel announced the news on a pair of Kansas City radio stations on Tuesday.
Lawrence, a junior, ran nine times for just 10 yards in the Tigers' opener, but won the starting job over three other backs in preseason camp.
Lawrence ran 73 times for 422 yards and four touchdowns last season.
David Ubben covers the Big 12 for ESPN.com.