Becks made his League debut as a Preston player in 1995 - on loan from United - and played alongside Moyes.
In his book 'My Side', Beckham said: "David Moyes was the top man.
"He was a centre-half and the kind who would throw himself into any tackle possible, even some that weren't.
"He'd be shouting, geeing people up and was passionate about winning games. He was club captain and talked to me and got me involved right from the off.
"It's not just hindsight - you could tell then that David was going to be a manager.
"He knew straight away what I was about, that I'd be quiet, keep myself to myself and just talk when I needed to.
"He put himself out to bring me into the group, to look after me, and I really appreciated that."