Paddy Crerand, who played 397 times for Manchester United and, like Roy, also featured for Celtic, couldn't believe the Irishman had hit the milestone already.
"You're joking?" he said.
"It's funny because I played in Cork in 1963 - one of my first games for United - and who do you think I met at that game in Cork?
"It was Roy Keane's father. He was a mad, mad United fan.
"I obviously met him hundreds of times afterwards when his son played for Manchester United but if ever a father got a thrill of his life, it must have been him when Roy signed for United.