For those of us of a certain vintage, it is staggering to think that Evan Williams is now 71 years old.

In my mind's eye this former goalkeeper - dark, handsome, and once described by Jimmy Johnstone's wife, Agnes, as the most attractive Celtic player - is still 29 and keeping guard for Jock Stein. And, memorably, is between the sticks on the night of April 19 1972 when Celtic faced Inter Milan in the European Cup semi-final.

It was a halcyon time for Stein and Celtic. From 1967 through 1974 they achieved the equivalent of a European Cup final or semi-final appearance every other year, and Williams came unexpectedly to the party. He had been a Wolves reserve goalie for the previous three years before Stein signed him in October, 1969. Williams went from a pay of £80 a week at Wolves to £50 at Celtic but within months would play in the final of Europe's elite club competition.

Some Celtic fans remember his fine display in that 1970 final against Feyenoord in Milan, when he actually preserved Celtic, even in defeat. Others, though, recall a near-frozen Williams being unable to keep Inter's penalties at bay in 1972 as Celtic strove to make their third European final in six years.

"The thing I remember about that night in Glasgow was how cold it was," he said. "It was April but I think there was even a wee bit of frost on the ground. I didn't have a great deal to do - unlike the first leg when I'd plenty - and by the time the penalties came round I was pretty cold."

After both legs had finished 0-0, Dixie Deans infamously blazed Celtic's opening kick over the bar before Inter went on to convert five out of five. "In the five minutes between the end of extra-time and the penalties Big Jock said to me, 'throw a coat around yourself,'" recalls Williams. "I said, 'no boss, gimme a ball, I need to dive about with a ball.' It was one of many disagreements - or debates - I had with Jock. He regularly accused me of representing 'the goalkeepers' union'."

Williams lasted five years as Celtic goalkeeper but his place seemed to be forever under threat. First Denis Connaghan arrived, and then Ally Hunter, as Stein clawed around trying to find the right man. But Williams prevailed, had a magnificent record against Rangers, and was well-loved by many Celtic fans. He would also speak his mind.

"I had plenty of debates with Jock Stein," he says. "I'd quite often say to him - as did Ronnie Simpson - that we should get a goalkeeping coach in. A goalkeeper has to do many different things: catch, kick, punch, parry, get his angles right. It's a specialist position. But Jock wouldn't hear of it.

"I'd been at Wolves where I had a brilliant goalkeeping coach in Fred Davies. He ripped my game apart and put it all back together. England at that time produced some of the best goalkeepers in the world: Gordon Banks, Peter Shilton, Ray Clemence and others. But at Celtic, Big Jock always insisted on doing it himself."

Ronnie Simpson, whom Williams effectively came to replace, once joked that Williams "was not five minutes in the door and he was telling Stein how to do things." But Williams, who stood just 5ft 10in, felt he had good evidence on his side.

"Not long after I arrived at Celtic in 1969 we faced Leeds United in the European Cup semi-final. Down at Leeds in the first leg big Jack Charlton had stood on my toes at corner kicks - that's what he did - and so Jock hatched a plan for the second leg.

"He wanted Billy McNeill to stand between me and Charlton. I said, 'boss, look, hang on...that means I've to climb above two of the tallest men in British football to get to the ball...that won't work.' It was one of many times I discussed or disagreed with Jock over my job."

Williams recalls that, while he took Stein to task, Stein would quite often defend him. When one reporter tried to point out to Stein that Williams was uncapped at international level, Stein growled: 'That disnae matter...he's the Celtic goalkeeper.' Their relationship was one of combative respect.

"I'd speak my mind, but not in a loud way, and Jock was always receptive, he would go away and think about it," says Williams. "Actually, Big Jock was great for listening and taking other opinions on board. And it was just as well, because Celtic didn't have quiet players at that time. Guys like Big Billy and Bertie [Auld]...they didn't t hold back. But Jock took things on board, he was an open book in that sense. Also, maybe 90% of the time he was right."

Now, nearly 43 years after that famous night in Glasgow, Williams says he looks on in awe at the current Celtic goalkeeper. He heaps praise on Craig Gordon, whom Williams believes may be one of the greatest goalkeepers ever to pull on a Celtic shirt.

"He's a superstar," says Williams. "I think he is absolutely top-class. What a con by Celtic and Peter Lawwell to get this guy for nothing after his two years of injury. And, though Craig is a very modern goalie on one sense, in another way he's just like the old days. It's all the rage today for goalies to fist or parry the ball, but Craig comes and catches it. If he is playing then I think Celtic will always have a chance."