Tuesday marks the 20th anniversary of the Scots-Canadian's takeover, which will be marked by a number of events at tomorrow's home SPFL Premiership match against Inverness Caledonian Thistle.
McCann will not be present but delivered his message in advance to the fans, crediting them for their role in returning the club to a much safer financial footing following a period of turbulence.
"I appreciate the club marking the occasion of 20 years since the takeover," the former owner said on the Celtic website. "In 1989 the process did not begin as a takeover but by 1992 it became clearly the best way forward.
"I want to thank the financing partners who joined me and had faith in my plan, especially John Keane and Albert Friedberg, the colleagues who worked tirelessly collecting shares and proxies and challenging the entrenched 'custodians', and, most of all, the many concerned supporters who campaigned and held the board and the bank publicly accountable.
"This was followed by the supporters stepping forward in great numbers by investing in Celtic's future with their hard-earned cash at a level never seen for a football club before or since because of the importance of the club in their lives.
"Like them, I care greatly for the values and history of the club that was founded for noble purposes to help fund the penny dinner tables of the poor in Glasgow's east end.
"I am very proud when I see Celtic's progress, its status in Scotland, and its worldwide reputation. Especially when I see the great work of Celtic FC Foundation carrying on the legacy of Brother Walfrid.
"Every supporter wants success for Celtic. That does not mean winning every game and beating every opponent, big or small.
"It does mean having a club that is the best it can possibly be, on and off the field, that never accepts second best, despite the obstacles it has had to overcome throughout its history. Celtic supporters want to be proud of their club. That's all they want. It is what they deserve."
Charlie Mulgrew was just seven years old at the time of the takeover but, growing up a Celtic fan, learned all about McCann's legacy.
"I was young at the time when Fergus arrived but I've heard a lot since," the midfielder said. "I vaguely remember when the club were struggling and I know how good he was for Celtic.
"As a supporter and player I'm really thankful for what he did for the club. The players who know about Fergus and are appreciative of what he did. He turned the club around and played a big part in the Celtic we know now."
McCann's prudent approach to rebuilding Celtic, compared to the more lavish ways of Sir David Murray at Rangers at the time, did not make him immediately popular among some sections of the support and he was even booed as he unfurled the championship flag in 1998.
It has taken the passing of the years - Rangers' financial collapse - to show that McCann was a man ahead of his time.
"At the time, I remember a lot of fans didn't fully understand what he was doing for Celtic," Mulgrew said. "But what a clever person he was. He transformed the place and we're all very thankful for it now.
"It's hard to believe he was booed once as he unfurled a flag. You can't imagine that happening now. But the supporters didn't realise back then how great he would be for the club. He was accused of being a bit tight. But now? As a fan, I can't thank him enough.
"Every time we run out at Celtic Park, a fantastic big stadium, you realise it was Fergus who gave us that. He did huge things for Celtic and I'm sure anyone who doubted him realises they were wrong.
"When you think now about clubs overspending, he was ahead of his time and knew what he was doing. There are a couple of clubs now who could be doing with a Fergus McCann.
"People didn't have a clue what he was trying to achieve back then. Celtic were very close to folding before Fergus came in but look at the club now. That shows how clever he really was."