Ryan Giggs has paid tribute to Sir Alex as the boss approaches his 25th anniversary as United manager.
The Reds' long-serving midfielder feels privileged to have enjoyed a great working relationship with his boss during his remarkable career and feels an incredible work ethic is the key to the Scot's success.
Sir Alex's legendary drive continues to fuel the club in its quest to remain one of the best in the world and it's typical of the focus of the man that he is playing down all the attention surrounding his latest landmark.
"The best piece of advice he's given me? To work hard," Giggs revealed to Inside United in an exclusive, lengthy interview. "You can have all the qualities in the world, but hard work is the key to everything. He’s seen plenty of quality players come and go at United over the years, but the main thing that sets great players apart from the rest is their work ethic.
"And he leads by example, of course. He’s always first in at the training ground and last to leave, and he wants to see that kind of mentality from his players as well.
"He just loves his job. He loves watching United play. He loves seeing players develop. He loves everything about his job. You couldn’t do what he does at his age and have the work ethic he’s got if you didn’t love it.
"Like I said before, his work ethic is incredible. We might have got home from a European away game at four in the morning, yet you can pretty much guarantee he’ll be first in at Carrington at 8am the next day – and will be last to leave.
"You’ll then stick the TV on later that night and see him at a function in London. It’s unbelievable."
Giggs' relationship with Sir Alex has obviously developed over the years as he's matured from rookie teenage talent to a distinguished elder statesman in the first team.