The former Manchester United forward came through the youth academy at Old Trafford during a period of dominance for the Red Devils, joining in 1999 as a trainee.
With United's senior side having just won the treble, it was clear that Johnson faced a baptism of fire as he looked to adapt to life at one of England's biggest clubs, something that he admits was hard-going as he attended training alongside some of the club's greatest-ever leaders.
Speaking to the Manchester Evening News, Johnson said: "I didn't eat butter for a decade because of Gary Neville.
"I struggled with body fat which was a big thing. He saw me putting butter on my toast at breakfast and he shouted across the canteen 'Eddie I am sure your body fat is too high.' And I froze. Even when I left the club I didn't eat butter!
"Sometimes I didn't want to see Gary Neville but when I left what I realised was that he was putting demands of what the first team expect from you.
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"Some people recognise what is going on and I probably didn't but I have taken those lessons into everything I do now and so I owe the club a lot.
"Ryan Giggs was fantastic with the younger lads in terms of support and guidance. Roy Keane was the same.
"I had a conversation with Roy Keane about going out on loan to Coventry and whether I should stay at United and go on a pre-season tour (in 2004).
"He told me if I was going to be at Coventry all season, which I was, then he'd recommend going in there early in pre-season, working hard and gaining that respect at Coventry rather than going on a first-team tour with United and coming in late and upsetting the balance."
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He added: "Most of the senior lads were great.
"There were only three people at United I never really liked, (Fabien) Barthez, Laurent Blanc and Ruud (Van Nistelrooy). Laurent and Fabien wouldn't acknowledge you which was poor considering the rest of the first team were great.
"I didn't necessarily dislike Ruud but he made it tough for you. Gary Neville made it tough but never made you feel like you were below him, whereas Ruud was different. I felt he didn't like the young lads. He couldn't stand Ronaldo at first! He was making run after run and Ronaldo would take ages to pass the ball."