IT IS no surprise that the views of Bertie Auld are uncompromising.
Those who watched him play would delight at his skill, admire his precision of passing and wince at his ability to render a dangerous opponent innocuous by the simple expedient of forcing him to play with a limp.
One of the memorable moments of Bertie belligerence was the European Cup semi-final of 1970 against Leeds United at Hampden when Auld introduced himself to John Giles with a tackle that felled the Irishman.
As he lay prone, one wondered if Giles was waiting for a physio or for someone to come on and put a chalk mark around his outline.
Auld - and again this is no surprise - is a fan of Roy Keane as a player and a character. The Lisbon Lion is "very surprised and disappointed" that the assistant manager of the Republic of Ireland could find the Celtic job resistible.
Auld, at 76, is as sharp as a pointed stud and remains a voluble sceptic of the modern game, and particularly of some of the values it espouses.
The midfielder won a European Cup and six titles with Celtic and is desperate for his club to find a man of stature to replace Neil Lennon.
He praised Keane's "knowledge and passion" for the game. Auld would talk to the Irishman when he was a player at Celtic in 2006, saying of those encounters: "You would be a fool not to be a good listener."
Keane, who became friendly with John Clark, Lisbon Lion and Celtic kit controller, made a good impression on Auld.
"Keane would have been box office in Scotland and he would have been great for Scottish football as he would have sold our game," he said.
"With Hibs, Hearts and Rangers in the Championship, Scottish football needs something to give it an injection."
He described the former Manchester United player, with a smile, of being "arrogant or ignorant, whatever you want to call it" but added: "Keane was always about the football and doing something special for the game and Celtic have missed out on a huge opportunity here."
His affinity with the Irishman extends into playing style. Auld told of the day he signed for Celtic at 16 and his father telling him he was now in the business of "kick and be kicked". He learned in his first reserve match that there was a physicality to the professionalism and adopted the practice of "getting in his retaliation first".
This strength extends to his opinions. "We should be looking to qualify in any trophy and we should be looking to go further than that and win it," he said of Celtic.
This level of ambition is bolstered by a playing career that included winning at the highest level at the club. The runners for the Celtic job have not yet attracted the Auld seal of approval.
"I was positive that Keane would be there that I never looked at any other candidate," he said.
"Celtic need both a manager and a coach. I look around and sadly I do not see another Jock Stein figure. Is there another Stein out there?"
The interview was in the Glasgow Film Theatre and this inquiry deserved a silence that would have graced a film screening.
"I look at Malky Mackay, Owen Coyle and Steve Clarke and they all have tremendous passion for the game," said Auld who managed Coyle at Dumbarton.
"Clarke has had some managerial apprenticeship with the people he has worked under," he said in reference to Clarke's experience working under Jose Mourinho at Chelsea and Kenny Dalglish at Liverpool. But he added: "Celtic as a club are bigger than that."
This was not said with any contempt for the quality of the candidates but with a sense of history. Auld, one of the glory Bhoys, is quietly insistent that the Celtic ethos should be to be the best in Europe not just Scotland. He talks of the need to entertain fans and overwhelm opponents.
His presence in the cinema was to promote a film about Stein and his conversation returned to the former Celtic manager without any prompting.
He said: "I promise you. Jock never spoke about systems or brought in a player to fit a system. He brought in a footballer who could play. He brought winners to the dressing room. He gave supporters what they wanted. "
Auld played for the Scottish League under Sir Matt Busby, met Don Revie at the time of the 1970 European Cup semi-finals and had many conversations with Bill Shankly. The defining figures of Manchester United, Leeds United and Liverpool had one shared trait.
"All the great managers in England looked up and admired the man from Celtic," said Auld. "It was awesome."
He reflected on the passion and skill of those great managers of the past but then made the biting tackle.
"Jock had that wee bit extra," Auld said. The Celtic search for a manager continues.
It is that "wee bit" that will be almost impossible to find.
Bertie Auld was speaking at an event to promote purpleTV's new documentary Jock Stein which airs on BBC ALBA on Monday at 9pm.