Irvine died at the age of 82 on Saturday after a long-battle with Alzheimer’s disease.
The centre-forward earned 23 caps and scored eight goals for his country between 1963 and 1972. At club level, he scored goals for Burnley, Preston North End and Brighton & Hove Albion.
Son Stephen Irvine is in no doubt that heading old-fashioned footballs on a regular basis caused his father’s illness.
He explained: “Heading a ball every day was the cause of my father’s Alzheimer’s and his death.
“He was an athlete and a man who always looked after himself. So even in his 80s his lungs and heart were strong. But his brain scan was similar to that of a boxer’s.
“When you think about it, he was heading the ball every day. Not a modern day ball, but a caser. Those old footballs were like medicine balls, so it was repeated blows to the brain.
“My dad loved heading the ball. I remember him playing head tennis with myself and my brothers in the garden. We didn’t know any better.”
In recent years, several high-profile players of Irvine’s generation have died with Alzheimer’s, including both Bobby and Jack Charlton, Denis Law, Nobby Stiles and Martin Peters.
Stephen believes that action must be taken to prevent the next generation of footballers suffering the same fate.
Willie Irvine leaps to head the ball while playing for Burnley
He said: “It’s an industrial injury.
“I love football and I know heading the ball is an important part of the game, but I think we need to help safeguard the next generation of footballers.
“We should curb how much heading a footballer does in training, or perhaps players should wear something similar to a scrum cap.
“Organisations like the PFA need to be forward thinking on this matter.”
Stephen was keen to thank both the Jeff Astle Foundation and the PFA for their help during his father’s illness. The Astle Foundation is named after West Bromwich Albion’s legendary striker Jeff who died in 2002. The charity is ran by Astle’s wife Dawn.
“Dawn Astle was magnificent with our family. She was there to help us at every turn. I was delighted to read a few weeks ago that she is to receive an MBE.
“The PFA now has its Brain Health Fund, which helped us with care costs for my father.
“Things have moved on from, say, 10 years ago. It’s a situation that is now being treated much more seriously than it was a few years ago.”
Reflecting on his father’s career, Stephen recalled the pride his father took in playing for Northern Ireland alongside his brother Bobby Irvine, who is still regarded as one of Linfield’s greatest-ever goalkeepers.
The brothers both played in a famous 1-1 draw with Spain in 1963, when Willie scored a late equaliser and Bobby was praised by the Spanish media for his spectacular saves.
“Dad loved playing for Northern Ireland and considered it a privilege. He always spoke with pride about standing for the national anthem before kick-off.
“He talked about playing alongside my Uncle Billy in Bilbao when they both had great games. It’s very rare that two brothers play together at international level.
“In the last few years, we watched old footage on YouTube. Quite recently, we watched Northern Ireland’s 1-0 win over England in 1972 that my dad played in.
“He was top goal scorer in the old First Division in the 1965/66 season with 29 goals for Burnley.
“If you did that today you would be a multi-millionaire, but my dad just got £60 a week and £5 per goal.
Willie Irvine is a Burnley legend
“Although that seems like nothing, it was decent money at the time. My brothers and I had a decent upbringing thanks to my dad’s football career, so we can have no complaints.
“He broke his leg at Goodison Park in 1967. He always told me he was never the same player after that, that he had lost a yard of pace.
“But Preston still paid £45,000 for him in 1968, and he scored goals there too.
“I wasn’t old enough to see him play professionally, but I watched him play in a few charity games and he was brilliant. He just seemed to glide past players.”
Bobby — a year older than Willie — now resides in a care home. Stephen believes it would be a fitting tribute if a street in their hometown of Carrickfergus was named after the brothers.
He said: “There was talk of it a few years ago but it never came to fruition.
“My father loved Carrickfergus. He was born in Eden but moved to the Woodburn estate when he was quite young. He and my uncle used to play football on the green near their house.
“It would be nice if their achievements were commemorated in some way.”
Willie Irvine’s funeral has been arranged for 2pm on Thursday August 14 at St John’s in Worsthorne, just outside Burnley. The procession will pass the centre-forward’s beloved Turf Moor, where he is regarded as a club legend.
“My father died at 3pm on a Saturday,” said Stephen.
“It was like he waited for that moment because football was such a big part of his life.
“We all knew it was coming, but honestly it’s still a difficult time. He was a brilliant man and a wonderful father.
“He is a hero on the pitch but to me he was just ‘dad’.”