Former Manchester City chairman David Bernstein has said it is "absolutely appalling" that Roy Keane is still accepted in football.
Bernstein was chairman of City in 2001 when Keane infamously launched a horror knee-high tackle on Alf-Inge Haaland which left the City man with an injury that, he would later admit, played a part in ending his career.
A feud between the two players began in 1997 when Keane ruptured his cruciate ligament while attempting to foul Haaland, who then claimed his opponent was faking injury.
Keane then got his revenge four years later in vicious style, landing his studs on Haaland's right knee during a Manchester Derby at Old Trafford. "I'd waited long enough. I f****** hit him hard. The ball was there (I think). Take that you c***," Keane later wrote in his first autobiography.
"And don't ever stand over me sneering about fake injuries. Even in the dressing room afterwards, I had no remorse. My attitude was, f***him."
In an interview with The Athletic, the bad blood continues to spill for Bernstein.
"I think, frankly, it's dreadful he's accepted in football the way he is," said Bernstein ahead of this Sunday's Manchester Derby and 20 years on since that tackle.
"After doing something like that, I think it's absolutely appalling. Whenever Keane turns up on television, I switch off. I just won't watch it. I'm appalled that he's still involved in football. It's just not right."
Keane ended up with a five-match ban and was fined £150k for the the incident, which Berstein describes as "the worst he has ever seen in football".
"Roy Keane stood over him and basically said, 'Take that, you bastard'," added Bernstein.
"It was done in cold blood. It was a cold-blooded incident. I have never forgiven Keane for that. From a personal point of view, that was the worst individual thing I've been directly involved in, and the worst I've ever seen on the pitch. As a human being, it was an awful thing to see."