The Football Association will not take action against the Swansea City defender Ashley Williams for kicking a ball at the head of Manchester United's Robin van Persie.

United's manager, Sir Alex Ferguson, called on the FA to ban Williams for a long time, claiming Van Persie "could have been killed" by the incident.

But the governing body will not instigate disciplinary procedures against the Wales international, who denied malicious intent. Van Persie was struck on the back of the head from close range while lying on the ground after being fouled but was able to continue without treatment. Williams was booked at the time by the referee, Michael Oliver.

Ferguson said after the 1-1 draw at Swansea: "In the Van Persie situation you can clearly see that he could have been killed. 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."

Meanwhile Ferguson looks set to escape punishment for comments he made about Oliver. Ferguson was angry that the referee allowed Swansea's equaliser to stand after Chico Flores fouled Van Persie during the buildup and described Oliver's performance as "shocking".

On Monday Premier League managers have came out in support of Williams. Wigan Athletic's manager, Roberto Martínez, who worked with him when in charge of Swansea, said the defender was "not a nasty footballer".

"You see the incident and it is a very, very dangerous situation," Martínez said. "If you see one of your players with a bang on the back of the head it is really dangerous and it can have bad consequences. You can understand that.

"I signed Ashley Williams for Swansea and I know his character inside out. I can guarantee you without even looking at the incident that he is not a nasty footballer.

"He is a winner and fully committed, a leader and a captain, and I don't for one second doubt that he did not do that on purpose.

"It is an action of the game. He can show frustration – it is an emotional game and it is very unfortunate that it hits Van Persie in a part of the body where he could have been hurt heavily, and you don't want to see that.

"But from my point of view, I know Ashley Williams really well – when you sign a player you find out about a player and I can guarantee you he is not the type of footballer who would do that on purpose."

Liverpool's manager, Brendan Rodgers, who worked with Williams at the Liberty Stadium until leaving in the summer, likewise felt the issue had been blown out of proportion.

"I think more has been made of it than what it actually was," Rodgers said. "When you slow it down and look at it 20 times it does not look good for Ashley.

"But I know the player well and it is just that split-second when you can see he is trying to clear the ball and unfortunately hits Van Persie right on the back of his head. Of course, it looks dangerous but knowing Ashley he won't have meant it."

The Queens Park Rangers manager, Harry Redknapp, also defended Williams, dismissing Ferguson's claim that Van Persie is lucky to be alive. "I don't see how he was going to be killed," Redknapp said. "He kicked the ball at him. I have seen worse things on a football pitch."

Alan Pardew also felt that Ferguson had overreacted but believes the Scot may have cooled down with the benefit of hindsight. "He genuinely felt that, I should think, at the time," the Newcastle United manager said. "If one of your players gets hurt or you think he was in danger, you are going to protect him.

"I think the one with Van Persie was perhaps not as bad as Alex at first imagined. Sometimes from the sideline, it looks a lot worse at the time."