(CNN) -- Manchester United manager Alex Ferguson has told CNN that football must eradicate all forms of racism, following recent high-profile incidents in England which have brought the matter back into sharp focus.
One of Ferguson's own players, France left-back Patrice Evra, was at the center of an incident last October which saw Liverpool's Uruguay striker Luis Suarez banned eight matches for using racist language.
Chelsea's John Terry has also been removed as England captain ahead of his July trial for alleged racial abuse of Queens Park Rangers defender Anton Ferdinand during a Premier League match in October -- a charge he denies.
"There have been a couple of examples recently, which is not good," said the 70-year-old Ferguson, who has been United manager for over 25 years.
"In 2012 you can't believe it. I think it was obvious maybe 20 years ago, but the improvements have been there for all to see."
Ferguson, who has led the Old Trafford club to 12 English titles and two European Champions League triumphs, said he did not understand why racism in football had once again reared its head.
"I've had some fantastic black players, absolutely magnificent black players, and every one I've enjoyed my working relationship with them. So I don't understand where it's coming from to be honest with you. I don't understand it at all," he said in a CNN interview at the Laureus Sports Awards.
"This is a moment where we have to take stock. I think they should do something about it if it's surfacing again and really be hard and firm on any shape or form of racism."
Suarez returned to action for Liverpool as a second-half substitute in Monday's 0-0 draw with Tottenham Hotspur and could again face Evra in Saturday's Premier League clash with United.
Liverpool have backed Suarez since the incident first came to light, with the squad and manager Kenny Dalglish wearing t-shirts with the 25-year-old's image on prior to a match with Wigan in December.
Dalgish remained insistent that Suarez should not have been banned following Monday's home game.
"Fantastic for us to get Suarez back -- he should never have been out in the first place," Dalglish told reporters.
"It would have been totally unfair to start him, having not played since Boxing Day. As much as we admire and love him, we've also got to manage him."