Stuart Pearce has refused to rule out the possibility of suspending Ben Thatcher for tomorrow's Premiership clash with Arsenal after confirming Manchester City have launched their own inquiry into the Welshman's horror challenge on Pedro Mendes.
Thatcher has been widely condemned for smashing his elbow into Mendes' face at Eastlands on Wednesday, with even Pearce now drastically revising his initial opinion that the incident was only worthy of a yellow card.
Pearce has already spoken to Thatcher once, claiming the defender had received a 'massive wake-up call' after seeing the incident on TV.
However, he will talk with the former Wales international again this morning, as well as chairman John Wardle and chief executive Alistair Mackintosh, before deciding what internal sanctions would be imposed on the 30-year-old.
'What happened on Wednesday was indefensible,' said Pearce. 'I have to talk with Ben this morning and I also have a meeting with the chairman. Between us we will decide what to do.
'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.'
Pearce did express his hope Greater Manchester Police, who have received numerous complaints over the challenge, do not carry out their threat to launch a criminal action against Thatcher.
'Anything that happens on a football pitch should be governed by the FA and FIFA,'' he said.
``Once you starting 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 who, thankfully, appears to have suffered no long term damage.
'Ben is distraught by this,' said Pearce. '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.'
City skipper Richard Dunne agreed with Pearce's theory that the incident had hit Thatcher hard, claiming he has noticed a massive change in the defender's attitude since Wednesday.
'Normally, he is such a bubbly character - but he has lost all that,'' said Dunne.
'He has been so down since it happened, I don't think he really wants to speak to anyone.
'It is difficult. Everyone saw what happened and it is not something that will just go away.
'Ben is such a nice fellow but this is something we could definitely have done without so early in the season and it has proved a distraction in terms of our preparation to play Arsenal.'