In the first instance, I would like to send my sincere condolences to his wife Myra and all of his family.
Sean was a great family man but, outside of them, Celtic was very much his extended family and he has always commanded a special place in the affections of everyone at the club.
As No.2 to Jock Stein, he played a key part in bringing about the European Cup success of 1967 and all of these other golden years.
Of course, along with Joe Connor, Sean played a key part in my discovery and development as a Celtic player and those of so many other great Celts like Danny McGrain and Kenny Dalglish, to name but two.
We all became known as the Quality Street Gang, but we were all members of the Celtic reserve side Sean nurtured and developed – and every one of us owes him a huge debt of gratitude.
My favourite little story about Sean revolves around an Old Firm reserve game at Ibrox.
It was 0-0 and I was up against Alex Miller,who was playing centre-forward back then. We were giving it laldy and, after one exchange, I retaliated with a poor attempt at a Glasgow kiss and received my marching orders, quite rightly, for my trouble.
It had been 0-0 at the time and, of course, we went on to lose. Afterwards Sean tore strips off me in the dressing room and told me I had let my team-mates, the club and myself down and to make sure it never happened again.
Then, as he walked out the dressing room, he turned to me and grinned: "The next time make sure you take him with you."
I was never sent off again though and that was down to Sean. He will be sadly missed.