For the man himself, the tragic events of January 2, 1971 have never been forgotten and never will as he still struggles to come to terms with what happened on that day all those years ago.

This weekend sees Rangers mark the 40th anniversary of the Ibrox Disaster, when dozens perished in a devastating crush on Staircase 13 at the end of an Old Firm derby.

"Sometimes I wonder where all the years have gone," Greig told Press Association Sport.

"The years have gone so quickly. Particularly at this time of year, you can't help but think about what happened 40 years ago.

"It was a sad, sad day and something you never forget.

"It's a very emotional time of year and, at New Year, I have always laid a wreath to remember those people.

"I know it's a time when people enjoy themselves but you can't dismiss something like that. If someone gets killed in a car smash, you can't understand it but you have to accept it.

"But for someone to go to a football match and not return, it's a terrible, terrible thing."

The match looked set to end in a goalless stalemate until Jimmy Johnstone opened the scoring for Celtic in the 89th minute but there was further drama to come when Colin Stein equalised for Rangers with just seconds remaining on the clock.

Most of the home fans in the 80,000 all-ticket crowd set off for home, satisfied with the result and completely oblivious to the disaster which was unfolding on a section of the East terrace.

Heading for the exits, some supporters stumbled and fell on the steep steps, with those around them suddenly engulfed in a terrifying crush, the barriers on Staircase 13 collapsing under the impact.

Among the 66 dead were many children, the youngest victim a nine-year-old boy who had travelled from Liverpool. Many more were injured.

"It was approaching the end of the match and we were losing 1-0," recalled Greig, who was Rangers captain at the time.

"Of course, you never like losing an Old Firm match. Out of the blue, Colin Stein scored an equaliser and, from staring defeat in the eye, we saved the match.

"The Rangers support were very happy about that and, when the final whistle went, we went into the dressing room quite relieved to have saved the match.

"Then, within a few minutes, there were murmurings coming from different people that something terrible had happened. That was first we knew about it.

"I was one of the last people to come out of the dressing room because I'd got a slight injury and had been getting some treatment and they started to bring one or two bodies into the dressing room.

"It's an unreal situation to see that. I walked down the tunnel and saw the bodies lined up along the side of the pitch.

"It was a cold, foggy day and it's something that never leaves you. It's etched on my mind and will always be there."

Lifelong Rangers supporter Ian Loch was among the hundreds of fans caught up in the crush but managed to scramble to safety from the Copland Road Stand.

He said: "The crush was happening in front of us as we headed down and out the concourse to 13. I knew it was an accident but I never really knew what was going on.

"It was just like a pack of cards, nobody knew what was happening in front of them and you had to shout 'get back, get back'.

"I was just trying to get out and I was in a state of shock when I did get out. I was just a boy really, I was only 19. And back then, my mum and dad didn't have a phone to find out where I was.

"I will always remember getting off the subway and walking up Dumbarton Road and an old boy came up to me and told me to get up the road home.

"I was in a bubble, I was dazed and shocked but when he said that, I knew I had to get home.

"It's a milestone for the club and fans to recognise. Forty years is a long time but it's really important for us to remember."

On January 2, 2011 - 40 years to the day - Celtic will again travel to the south side of Glasgow for the New Year Old Firm derby.

The occasion will be marked by a number of tributes.

There will be a minute's silence prior to kick-off, both teams will wear black armbands and areas of the stadium will be set aside for floral tributes.

Greig and Billy McNeill, the Celtic captain of that era, will lead out the teams.

"It's a long time since we've done that," said Greig.

"It will be a proud moment for Billy and I think it's great that he's coming along to do it. It will be a very proud moment for myself, and a very humbling moment.

"Anything I can do to try and pay my respects to the relatives of the deceased, I'm only too happy to do so.

"We are having a service the day after the game and we are hoping to pay our respects on the 40th anniversary.

"Hopefully it goes down well with the relatives and it's a fitting tribute to the people who lost their lives."