Chris Hutchings departed Wigan on Monday after just six months in charge, and Clark is urging Premier League chairmen to be patient before parting company with their manager.
Ex-Toon Defender Says 'Patience' Brings Success!
Clark: "We like to think chairmen would look at this (Ferguson's reign) and say 'wow'.
"It took him a while to turn it around at Manchester United and that's a lesson. I'm not sure you would get that length of time today, but it just proves the value of giving your manager a bit of time and help to turn things around.
"He's the ultimate example of patience and the ultimate role model for managers to aspire to.
"We would like to think that if they (chairmen) pick the right man they would give them a bit more time to turn things around. It's not a simple thing that can be done in five minutes.
"I don't think we'll see anything like this again in the future.
"We haven't seen it very often in the past and even less likely to see it in the future.
"The money that's come in has changed the game. It would be very difficult for anyone to survive at a club for 21 years in the future, I wouldn't hold my breath for that.
"It's the nature of the business, managers tend to move on as well."
Clark was a Fairs Cup winner in 1969 with Newcastle.
Brian Clough took him on a free transfer when it was thought his career was over, but Frank's went on to win a League title medal, 2 League Cup winners medals and a European Cup winners medal with Nottingham Forest.
Born in Highfield, Consett, he signed for Newcastle from Crook Town.