Sir Alex Ferguson was renowned for his no-nonsense approach to management, bringing out the famous 'hairdryer treatment' on a number of occasions throughout his 26 year spell at Old Trafford.
It was a "I'll respect you and you will respect me" kind of culture at Manchester United, so when a player stepped out of line, or did something that the boss disagreed with, they soon knew about it.
Ferguson, as a result of his high standards, fell out with a number of players, including the likes of Roy Keane, Ruud van Nistelrooy and Paul Ince, to name just a few.
But perhaps the most famous example of them all was David Beckham, whose relationship with the boss was arguably the most difficult. *Cough* flying boot incident *Cough*
Beckham himself admitted that he made mistakes during his time at Old Trafford that led to a breakdown in relations with Sir Alex, and a story involving a Mohawk hairstyle in 2001 has left me day-dreaming about this incredible turn of events.
I'll let the man himself describe what really happened:
"I walked in the changing room and he hadn't seen it because I was too scared to even show him." Beckham said in a recent interview with Otro.
"I'd gone into training the day before with a beanie on, trained in a beanie, gone back, walked in the hotel, had a beanie on, had dinner, beanie on, breakfast beanie on, bus on way to stadium - beanie.
"Then as I got ready for the game I took it off, he said 'go and shave it off'.
"I giggled and he was like 'no, I'm serious. Go and shave it off'. So I had to find a pair of clippers and I shaved it off in Wembley Stadium. Manager always rules."
Can you imagine that kind of thing happened today? Beckham certainly can't:
"It's a lot more normal to do it these days, it's a lot more normal to have a mohawk or a tattoo on your neck or wear coloured boots." he said.
"When we were growing up the manager wouldn't let us even step on a pitch wearing a pair of red boots or a pair of white boots. Simple as that. Things like that have definitely changed."