Moyes worked with Beckham when he played on-loan at Preston North End.
"When he came to Preston on loan from United in 1995 I was player/assistant manager there to Gary Peters," said Moyes. "David was frail but he was confident. He had ability and we saw that in his first game. He came on as a substitute against Doncaster and scored direct from a great, inswinging corner.
"The manager put him on all free-kicks and corners. Next week, he scored a free-kick against Fulham. He was only with us a short while but when he went back he more or less went straight into United's team. We didn't get promoted that season but David and his father turned up at the game the next year when we did get promotion.
"I've always found him humble and a very kind man. He was a terrific player and he went on to become a great player. He's had a huge impact on the game."