Peter Grant was one. The midfielder and former captain, who spent 15 years at the club from 1982, recalls fraught negotiations with the owner, not least relating to his testimonial at the club against Bayern Munich in early 1997.
As much as he admired the businessman's "determination and guts", he found him an odd character who changed the nature of the club forever and whose penny-pinching at times drove him to distraction.
"Fergus was more like a cartoon character than anything else to the players," said Grant. "I took on the captaincy for a while and would often come out of meetings with him a bit bamboozled. I'd point out that players hadn't been paid bonuses and were a bit concerned.
"He'd counter: 'What's a bonus? You shouldn't be getting bonuses.' But I had to say, with all due respect, it was him who sanctioned the contracts. Some were on good wages, others not so great, but they had been agreed.
"He watched every single penny: he was right on top of the pocket money we got for pre-season trips or how much the dry-cleaning bill for the kit was. Questions were asked as to where that money had gone.
"I remember Paolo di Canio getting a bill to tax his club car. He wasn't expecting this and that was one of the reasons he decided he deserved more respect. Paolo then wanted to know where all the money for Di Canio scarves and shirts was going! He said: 'Not Fergus McCann. Di Canio!' But Fergus never gave you a buck for nothing."
Things got particularly fraught when McCann took advantage of the club's exit from the Uefa Cup to put on a friendly against Barcelona in November 1996.
"He thought Celtic were going to have to pay for my testimonial," said Grant. "I had to explain it would cost him nothing, my committee would pay for things and, in fact, Celtic would make money out of the game and it was the people who turned up that paid for the testimonial.
"Then he put this game on against Barcelona and I thought: 'Bloody hell, what are you doing to me?'
"I wasn't too happy and told him that because there's only so much the Celtic fans could be expected to fork out. I couldn't believe we were playing Barcelona when he knew we had Bayern Munich coming up two months later.
"It was ridiculous. We had to keep fighting to get the best time for my game. I was coming to the end of my Celtic contract, I had waited four years … to get this game on and eventually we'd got everything put in place. I was really disappointed."
History has proven McCann a hugely progressive figure in the club's evolution, but managers such as Tommy Burns became collateral damage. "Celtic was a welcoming, family club and all of a sudden I realised it turned into the feeling of a business - and a fantastic one at that," said Grant.
"I guess it had to for what his plans were. But I still think Tommy's sacking was a massive wrong. Tommy had that fantastic side with di Canio, Jorge Cadete, Thom and wanted to kick on and knew what it would take to get there. He wanted David Ginola.
"But Fergus was worried about the cost … Fergus didn't want to raise the bar on the financial side. Tommy paid the price for that and that was really disappointing."
In the end McCann had right on his side. "Fergus thought we'll live within our means and that's the way he wanted it," said Grant. "There's no doubt the foundation he laid down means Celtic will never go back to the upheaval. He went away with plenty money, but you have to credit the job."
McCann was always more than just a money man. He restored Celtic's link to charitable causes, and launched the Bhoys against Bigotry campaign, but his fiscal prudence set standards which still hold today.
If history - and particularly the financial problems encountered by David Murray - vindicate such an approach, Neil Lennon is the latest manager to experience the same occasional frustrations.
"Maybe they [Rangers] were over-spending and maybe Fergus was right in terms of the realistic value of players and wages at times," said Lennon. "But he did push the boat at times for players and also on decent wages. Maybe not in comparison to what was happening across the road, but it was still good money. I have not been in that situation with Dermot, but plenty of times with Peter Lawwell! Peter is carrying on the honourable traditions."