Denis Law, one of the most celebrated footballers in Manchester United’s history, has said he has been diagnosed with Alzheimer’s disease and vascular dementia.

Law, 81, was part of the famous Holy Trinity, alongside George Best and Sir Bobby Charlton, who helped bring the glory days back to Old Trafford following the Munich air crash of 1958 in which eight club players perished.

Striker Law scored 237 goals in 404 appearances for United and played 55 times for Scotland during a gilded career in which he won four major trophies, including the 1968 European Cup (now known as the Uefa Champions League). Only Wayne Rooney and Charlton have scored more goals for the club than Law, who is affectionately known as “The King” by United supporters.

Law, who won the Ballon d’Or in 1964, said the road ahead would be “hard, demanding, painful and ever changing”.

“I’m at the point where I feel I want to be open about my condition. I’ve been diagnosed with ‘mixed dementia’, which is more than one type of dementia, in my case... Alzheimer’s and vascular dementia,” Law said on United’s website.

Law is the eighth member of Sir Matt Busby’s 1967-68 squad who is known to have been diagnosed with dementia. Last year, at the age of 83, Charlton, a survivor of the Munich crash, was diagnosed with it.

Law described the disease as “incredibly challenging”.

“You hope that it won’t happen to you, even make jokes about it whilst ignoring the early signs because you don’t want it to be true,” Law added. “You get angry, frustrated, confused... worried for your family, as they will be the ones dealing with it. However, the time has come to tackle this head on, excuse the pun.

“I recognise how my brain is deteriorating and how my memory evades me when I don’t want it to and how this causes me distress in situations that are beyond my control.”

Recent research by a team from the University of Glasgow has found that some positions in football increased the risk of subsequently suffering dementia, with defenders — who head the ball most often — at by far the greatest risk.