JOHN Hartson always put his head in where it hurts. So it was no surprise yesterday to hear the former Celtic giant sympathising with calls for greater studies into the link between heading a football and dementia in the wake of the sad loss of Billy McNeill and Stevie Chalmers, two Lisbon Lions who both suffered from that condition in their latter years. “It was really sad news about Stevie,” said Hartson. “I know his daughter Natalie as she’s based in Swansea.

There’s never been a man who’s scored a bigger goal in Celtic’s history,” he added. “I loved scoring big goals. I got that one at Anfield and managed nine against Rangers as well as last minute winners.But to be the man who scored the winning goal in the European Cup Final makes him immortal. What a moment that must have been for Stevie.

“To have lost both him and Billy – who was an absolute icon to the Celtic family – in the space of a week is really hard. I feel very privileged to have been in the company of both men. I sat next to John Clark at the player of the year awards and he was saying that Billy in the last year didn’t have much quality of life. He’d stopped coming to Celtic Park towards the end as he was suffering that badly.

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“John said that at least he’s in a place now where he’s not in any pain. It is extremely sad and it’s a blow for the Celtic family that two of their greats have sadly left us.”

Hartson, whose testicular cancer spread to his brain, carries many a scar on his forehead. “Most men don’t have a scar and I’ve got five on my head,” he said. “Look at the head trauma that I’ve had. Listen, I’m 44. I hope I make it to 60. You just don’t know.

‘Chris Sutton and Alan Shearer have both gone on record and said they believe [here’s a link between heading the ball and dementia]. The great Jeff Astle suffered from the same condition and he was a great header of the ball.

“I’ve not delved into it enough really. The balls were heavier back then. People are saying that potentially there could be a link between heading the ball and that condition.

“Nowadays the balls are light, they fly through the air and move. Years ago, when the boys we are losing now were playing, it was different. They do say there might be a link and potentially there might be as a lot of these ex-players are suffering from dementia. It’s generally centre halves and forwards. And I spent all my career heading the ball.”

**John Hartson was speaking at The John Hartson Foundation Golf Event at Turnberry. In its ninth year, The Hartson Foundation helps to raise awareness on testicular cancer and will go through the £1million this year on funds raised.