Former Manchester United striker Law reduced his former team-mate to tears by agreeing to write the foreword of McCalliog’s new book after revealing his vascular dementia and Alzheimer’s condition earlier this year.
"He was the benchmark growing up, we used to ” McCalliog said, “but the one thing about Denis Law is he is a wonderful human being.
"I cried when he said yes, and I’m still a bit emotional about it.”
Now he hopes as more and more studies research and analyse the disease, he hopes future stars won’t suffer like his 1967 team-mate Law.
"Heading a wet football 20 or 30 times in training a couple of days a week is probably not the best thing to do but that was the way it was back then and sadly we are finding out more and more about it and as life goes on hopefully a lot of others won’t suffer like a lot of my ex-team-mates and friends are at the moment,” he told Sky Sports.
McCalliog is a well-known supporter of the Football Memories project which uses reminiscence therapy alongside football to support people with the conditions, and launched the book with project director Richard McBrearty at Hampden.
His book looks over his 17-year career from Scotland schoolboys to spells at Chelsea, Wolves, Sheffield Wednesday and Manchester United and that particular day at Wembley in 1967 that coined a legend, and crowned Scotland unofficial world champions, with his third and winning goal against the reigning World Cup winners, England.