With Van Persie falling to the ground after he was fouled on the edge of the area, Williams cleared the ball into the back of the Dutchman's head from close range. Van Persie reacted angrily and squared up to Williams with referee Michael Oliver electing to book both players.
"The Van Persie situation you can clearly see that he could have been killed," Ferguson said on Sky Sports News. "The FA has got to look into it regardless that he has been given a yellow card. He should be banned for a long time because that was the most dangerous thing I've seen on a football field for many years."
He added: "It was absolutely deliberate. The whistle has gone, the game has stopped and he has done that right in front of the referee, he could have killed the lad.
"It was a disgraceful act by the player, he should banned for a long time."
Williams however looked to downplay the incident.
"I tried to clear the ball it hit him on the head," he added. "I was trying to clear the ball.
"He was obviously a bit angry about that.
"It was a much ado about nothing."
- Sports & Recreation