Dwight Yorke praised the continuing determination of former boss Sir Alex Ferguson, who is celebrating his 26th year at Old Trafford.
Ferguson has won 12 Premier League titles, two Champions Leagues and five FA Cups - among many other trophies - since arriving at United in November 1986 and this month a statue was unveiled of him outside Old Trafford.
"He's a great manager and a great personality," said Yorke, who won three Premier League titles and a Champions League winners' medal playing under Ferguson between 1998 and 2002.
"There's a statue of him outside Old Trafford now for what he's done for the club and the level he's taken Manchester United to - and deservedly so.
"He's an unbelievable man, a one-off."
Yorke told Sky Sports News it would be easy for 70-year-old Ferguson to retire from the game, but believes his continued commitment is testament to his love of the sport.
"He's still there with the players every day," said Yorke.
"He loves turning up at the training ground and unbelievably still wants to win trophy after trophy; he's still got the determination. He sets the benchmark for every manager that's out there.
"The one question we keep asking is 'what inspires him?'. I think it's the desire to win at all costs.
"He's a football man through and through. He loves being at United and it seems to be all he's interested in.
"It's cold and windy and really horrible at this time of year and for a man who is going to be 71 in a few weeks' time you'd think he would pack it in and go somewhere sunny and enjoy his retirement, but he's at training everyday watching players, encouraging them.
"I left the club a number of years ago now but he still lets me back in and makes me feel part of the club, part of the history of the club, whenever I go back there.
"I'm very grateful he gives me the opportunity to come back to club and I'm also doing my coaching badges there - and Sir Alex Ferguson is making it all happen for me."
Another icon of Manchester United, Eric Cantona is also celebrating an anniversary this week - Tuesday 27 November being exactly 20 years on from when he first arrived at Old Trafford.
Yorke never played with the legendary frontman, joining United a year after the French ace had retired, but says his influence was still felt at the club when he arrived and his impact lasts until this day.
"I've not had the pleasure of playing with Cantona but when I joined the club I heard so many stories about him," said Yorke.
"He's one of the superstars of the club, an iconic figure at Manchester United. He set the benchmark for the young team of Paul Scholes, David Beckham and Ryan Giggs which turned them into major superstars.
"There were stories of extra training sessions, Cantona taking a bag of balls away to practice after every training session and the young players caught onto that.
"Eric set the benchmark and people like myself followed and tried to live up to that expectation."