Back in those teenage days when fan-dom can veer towards obsession I came across a cartoon that had been made a year or two earlier featuring The Beatles.

Delightfully daft, the plot was probably inspired by the behaviour of groupies. A coven of witches pursued John Lennon everywhere, having misunderstood a recipe instruction which told them their noxious potion needed to include the brains of a beetle.

What the other members of the band ever thought of that characterisation of the man around whom they originally gathered has passed into the mists of time, but I can remember thinking the animators got it just right.

Lennon was the brains of the Beatles, just as Paul McCartney was its heart and George Harrison its soul. Truth be told I was never as fussed about poor old Ringo.

Lennon's "working class hero" intellect, was formidably obvious in his lyrics while, like all sentimental Celts, I can have a good smile or a greet when exposed to some of Macca's more magical melodies. Harrison, though, was always my personal favourite, largely because it felt as if the band's third great songwriter always sought to make sure that those around him remembered what they were trying to do and why.

All of which came to mind this week as I thought about this week's little bit of history, as Glasgow Warriors to host the first RaboDirect Pro12 semi-final to be staged in Scotland, and the role played by big Al Kellock in getting them there.

The club captain has not featured anywhere near as often as he would like to this season, only partly because of injury. Yet whether on the field, on the bench, running on to the pitch as a water carrier, or working the room as he did so engagingly at the Pro12 Awards dinner last weekend, he remains the man who gives all around him an understanding of what his club is all about.

It has been an interesting couple of years since the day I caught Kellock's eye as he entered a press conference at which the Scottish Rugby Union hierarchy was seeking to explain its sacking of a coach who, that season, was on the point of taking Warriors to the play-offs for the second time in three years.

Kellock looked as uncertain as anyone regarding the potential impact that decision would have on the club, but there was no doubt he would try to minimise the fall-out.

It had been a masterstroke by Sean Lineen to recruit Kellock from Edinburgh, where he had learned his trade under the great Todd Blackadder, man of 'Mana', that marvellous Maori word that means someone is possessed of an almost spiritually-based authority.

A native Glaswegian, Kellock understood intuitively what was required to rid Glasgow of their "nice to watch, nice to play against" image.

Amid all the upheaval, which has included some rather disturbing off-field shenanigans, the role of the Kellock as club captain was vital.

The 'Killer Bs' - that devastating back row of John Barclay, Johnnie Beattie and Kelly Brown - and Bernie Stortoni have gone but heart transplants are almost routine these days. Generating energy and passion was always achievable among new personnel.

As for brain-power, Chris Cusiter - the Sorceror's Apprentice ever since Lineen took him to Boroughmuir - could ensure that the right decisions continued to be made. It is telling that, when even Cusiter is being allowed to leave - a decision which may yet prove costly given the difference the law graduate's shrewdness made when he was finally re-established as starting scrum-half this season - Kellock alone among those key figures has had his contract extended. His influence in the camp seems to have been recognised by his employers.

The one natural leader Scottish rugby has produced in the past decade and more, Kellock has not always been treated with the respect his importance to club and country deserves when it comes to selection.

The management seem to know they can take it for granted that, whether or not he takes his rightful place at the head of the team this week and next, the man who has put the soul into Glasgow Warriors will ensure that all concerned know what they are trying to do and why.

I suspect I am not alone in believing the captain should be in the semi-final starting line-up when it is named today.

And Another Thing

Several weeks have elapsed since I observed that the BBC's Scottish rugby commentators perhaps needed to be a little less diplomatic in their utterances.

It is to Andy Nicol's considerable credit, then, that rather than taking umbrage, he absorbed Herald Sport's recent series with former Scotland coach Frank Hadden - which looked at what must be done to save Scottish rugby - and sent the following reply.

"Just read your articles with Frank Hadden with interest and they confirmed my long-held belief that he is the most qualified man in Scotland to lead the sport forward and should be appointed director of rugby immediately. The credentials of the incumbent fail miserably in comparison."

The discussion continues . . .