According to a complaint filed in Lafayette County Circuit Court on Friday, plantiff Matthew Baird claims Denzel Nkemdiche punched him from behind and knocked him unconscious. The complaint then says Robert Nkemdiche and five others -- who were not named -- began to kick and stomp Baird while he was on the ground.
Baird's attorney didn't immediately respond to a message seeking comment. The story was first reported by foxsports.com.
The Ole Miss administration says it supports the Nkemdiches, who are brothers.
"When this alleged incident occurred, the proper authorities investigated the matter and could find no evidence of wrong-doing related to Denzel and Robert Nkemdiche or any other members of our football program," Ole Miss athletic director Ross Bjork said. "This is a personal matter for them and we will support Denzel and Robert while they defend themselves in this civil case."
The Nkemdiches, who are from Loganville, Ga., were both important for the Ole Miss defense last season.
Denzel Nkemdiche, a sophomore linebacker who was an All-Southeastern Conference selection in 2012, is already suspended indefinitely after being arrested and charged with disorderly conduct and disturbing the peace last weekend.
Robert Nkemdiche was the consensus top recruit in the nation in 2013. The 6-foot-5, 294-pound freshman defensive end was second on the team with eight tackles for a loss last season.