Sheffield Wednesday goalkeeper Chris Kirkland was attacked Friday by a Leeds fan who entered the field after an equalizing goal in the Yorkshire derby in the second-tier English Championship.
The fan appeared to punch Kirkland in the wake of Michael Tonge's 77th-minute equalizer, while unsavory chanting also marred the night.
Wednesday manager Dave Jones called for Leeds fans to be banned from "every away ground."
"They are vile animals," Jones said. "You talk about racism, the chanting, that's a form of racism."
The offending fan has been identified by police. The suspect, who has been named on social media sites but not by police, has yet to be arrested.
"We are dealing with the complaint made by the player and we are currently taking statements, collating evidence and making inquiries to locate and arrest the offender," said South Yorkshire Police senior investigating officer Mark Monteiro. "We are also using CCTV footage from around the ground to identify suspects who may have been responsible for other offenses before, during or after the match."
Leeds manager Neil Warnock called for Kirkland's assailant to be given a prison sentence as he described the events at Hillsborough as "an absolute disgrace."
"I felt embarrassed to be a manager when I saw that," Warnock told Sky Sports 1. "I thought it was an absolute disgrace. I think they should get the guy and prosecute him and put him in prison. (Kirkland) went down like a ton of bricks, but that doesn't make a difference. Nobody should be on the pitch doing that.
"I hope we can make an absolute issue of it. He spoiled everything for everyone. I've not enjoyed that when I see a moron like that. I am not proud of being Leeds manager when I see that. I don't mind the rivalry between us -- there was a great atmosphere. To see things like that on the field of play, there is no place for it -- I am absolutely embarrassed."
With Kirkland grounded, the man returned to the stand among other away fans, while a number of other visiting fans ran on and off the pitch. Bottles also were thrown onto the pitch from the away end.
Support staff was quickly on hand to attend to Kirkland, who was treated for some time but completed the match, although he was visibly shaken.
"He's sore," Jones said. "If he'd have stayed down, I wonder what would have happened. I have an ill goalkeeper. They should be punished."
Refusing to accept just one Leeds fan had been in the wrong, regarding the chants that rang out midway through the first half, Jones said: "It wasn't just one chanting. That was from their area, too. I've had it for 12 years. It's just upsetting that they're allowed to do it. They should be banned from every away ground."
Jones went on to criticize Warnock for allowing his players to clap at the fans at the end of the 1-1 match.
"And then to go and wave at them ... not in my book. You don't wave at them after that," Jones said.
Warnock defended the majority of his team's fans.
"Dave was saying we shouldn't thank the crowd, but our crowd were fantastic but we've got one moron and I can't tolerate that," he said. "... All of them apart from one moron were excellent tonight."
A large number of the Leeds fans sang about the child-abuse charges Jones once faced (the charges were dropped), while former broadcaster Sir Jimmy Savile, now the subject of a similar police investigation, seemed to be heralded in song.
The Wednesday fans also stoked things up with songs about the two Leeds fans killed in Turkey in April 2000, with the Leeds supporters responding by throwing bottles onto the field and clashing with police.
"I thought it had gone out of our game. The authorities have to look at it and sort it," Jones said. "I'm talking about an incident when we should be talking about the football. We're talking about vile animals. That's what they are. We talk about racism, but that, we need to sort that."
Leeds issued a statement after the game pledging to hunt down the man involved in the Kirkland incident.
"Leeds United Football Club would like to publicly apologize and condemn the action of the fan who came on the pitch and attacked Sheffield Wednesday goalkeeper Chris Kirkland. The club will fully co-operate with the police and the football authorities in identifying the individual concerned," the statement said.
Warnock said the police were not to blame for the lapse in security.
"If you've got a moron who wants to get past the police to run on the pitch, no police, no matter how many you get, you're not going to stop him," Warnock said. "Get it custodial, get him sent to prison and stop it."
Information from Press Association was used in this report.