Greater Manchester Police have confirmed they will investigate Ben Thatcher's challenge on Pedro Mendes during last night's Premiership match between Manchester City and Portsmouth at the City of Manchester Stadium.
The Manchester City full-back crashed into the Portuguese midfielder in the second half of the goalless draw at Eastlands.
The Portsmouth player was knocked unconscious and spent the night in hospital.
A spokeswoman said today: 'Greater Manchester Police has received a number of complaints from members of the public following an incident in which a player was injured during the Manchester City v Portsmouth match on Wednesday 23 August 2006.'
Meanwhile, Football Association officials are looking at their own regulations for punishing players to see if further action can be taken against Ben Thatcher for his crude challenge on Pedro Mendes.
The Manchester City full-back crashed into Mendes in the second half of the goalless draw at Eastlands, with the Portsmouth player spending the night in hospital.
'We are looking at whether this may possibly be an exceptional case and what options may exist under our disciplinary regulations,' an FA spokesman told PA Sport.
Referee Dermot Gallagher gave Thatcher a yellow card for the challenge, meaning the 30-year-old defender should escape further sanctions under strict disciplinary guidelines.
The tackle, which sent 27-year-old Mendes into the advertising hoardings, was condemned by Pompey boss Harry Redknapp and later by television pundits who examined the forearm challenge.
'The FA have to do something,' said the Portsmouth manager. 'It is there for all to see. I do not want to see anyone suspended but how could that possibly not be a red card? What do you have to do to get a red, kill someone?'
Mendes has left hospital and will travel back to Portsmouth with club officials.
'He will continue to be under medical and neurological supervision during the forthcoming week,' read a statement on Portsmouth's website.
Greater Manchester Police confirmed it had received a number of complaints about the incident and that they would be talking to both clubs, Mendes and Thatcher.
