Portsmouth midfielder Pedro Mendes has described Ben Thatcher's challenge as the worst moment of his career.
Mendes was knocked unconscious and spent the night in hospital after Manchester City defender Thatcher hit him with his arm.
Mendes says he will help with any inquiry into Thatcher's actions
"The moment was terrible. After the incident, I do not remember anything after that until I was in hospital," Mendes told the Daily Mail.
"It is the worst thing that has ever happened to me in my career."
News conference: Manchester City boss Stuart Pearce
Thatcher received only a yellow card for the challenge but Greater Manchester Police and the Football Association are carrying out further investigations into the incident.
Mendes was released from hospital on Thursday but will undergo medical and neurological supervision over the next week before he is cleared to play again.
Ben is distraught by this. He now realises just how bad the challenge was and his face was ashen when I spoke to him
Man City boss Stuart Pearce
The 27-year-old said: "At first I had real fear about possible after-effects of the incident but the doctors are optimistic I will be okay.
"The tackle was totally unnecessary but I am not the referee and the decision from now on does not depend on me.
"As far as I am concerned this match is finished for me now and we move on.
"This subject is now in the hands of Portsmouth and the FA. If am called on to speak then I will give my opinion."
Meanwhile Thatcher's manager Stuart Pearce will meet his chairman John Wardle and chief executive Alistair Mackintosh on Friday to decide on the internal punishments to be handed to the 30-year-old.
"What happened on Wednesday was indefensible," said Pearce. "Any form of discipline will be discussed at board level, kept internal and we will move on from there.
"But I can assure everybody, this has hit the player very hard. There is no bravado about him. He has gone home, turned the TV and seen the challenge. The more you watch it, the worse it gets."
However, the City manager does not believe Greater Manchester Police should become involved.
I know Ben Thatcher and off the field he is genuinely a good lad but on the pitch he sometimes loses it
"Anything that happens on a football pitch should be governed by the FA and Fifa," Pearce said.
"Once you start involving the police, the floodgates can open and you could end up with a situation where players are arrested during a game."
Thatcher has already written a letter of apology to Mendes.
Pearce added: "Ben is distraught by this. He now realises just how bad the challenge was and his face was ashen when I spoke to him yesterday.
"He is disgusted with himself and there is no way I, or anyone at my club, can defend it. People are having a go at him but, in all honesty, he has not got a leg to stand on."
Portsmouth manager Harry Redknapp, who condemned the challenge immediately on Wednesday, spoke about the incident again on Friday.
He said: "I don't want to see the police getting involved. It is football's problem and the game should deal with it.
"Let's hope that the FA can take the most appropriate action possible. It was one of the worst incidents I've ever seen in the game.
"Pedro is disgusted by what has been done to him. I know Ben Thatcher and off the field he is genuinely a good lad but on the pitch he sometimes loses it.
"There is no way I can defend what he did. You cannot defend it and I've told Stuart Pearce (City's manager) he can't defend it either. There is no way of defending it.
"Stuart is apologetic. Of course, he is but something has got to be done. Let's be honest, it was brutal."