Sir Alex Ferguson wasn't one to mince his words.
And when David Beckham - arguably the very first celebrity footballer - strolled into work one day with a mohawk, the legendary Manchester United boss wasn't impressed.
Beckham's relationship with Ferguson wasn't always rosy, with the pair clashing on on-and-off-the-pitch related matters from time to time.
Ferguson also famously kicked a boot, which hit Beckham in the face and cut his eye, not long before the midfielder left Old Trafford for Real Madrid.
On the 2001 'haircut incident' neither man was hurt, fortunately, but Ferguson made his feelings felt in regards to Beckham's latest controversial trim back in 2001.
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Reminiscing on his conversation with Ferguson at the time, as part of the 20th anniversary of United's Treble on Otro, Beckham said: "I walked in the changing room and he hadn't seen it because I was too scared to even show him.
"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'.
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"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."
Football has changed a lot since Beckham ruled the roost, and the 44-year-old reckons the situation wouldn't play out in the same way today.
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He added: "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.
"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."
