Missouri can add one more player to its list of injuries.
Missouri coach Gary Pinkel announced the news on a pair of Kansas City radio stations on Tuesday.
Lawrence ran nine times for just 10 yards in the Tigers' opener, but won the starting job over three other backs in preseason camp.
Lawrence is the latest in a long line of key players injured for the Tigers, which began with another running back this preseason when Marcus Murphy was ruled out for the season after undergoing shoulder surgery.
Senior All-Big 12 left tackle Elvis Fisher will miss the season with a torn patellar tendon in his knee, and a knee injury will keep starting center Travis Ruth out of Friday's game.
In the win over Miami, senior linebacker Will Ebner suffered a high ankle sprain and senior defensive end Jacquies Smith suffered a dislocated elbow. Both are out for Friday's game.