The players knelt in a moment of prayer after the injury.
Arkansas later officially diagnosed the injury as a stinger, which is less serious than what had been feared initially. He was taken to a hospital as a precaution.
Much of the immediate worry resulted from the fact that Williams suffered a serious neck injury as a freshman in 2015. So the initial concern was that Williams had sustained a similar injury.
Coach Bret Bielema told reporters after practice that the stinger was unrelated to his 2015 injury.
It is unclear when Williams will be able to resume football-related activities.