After retiring from playing Harrison entered coaching. Harrison took the post of youth team manager. It was his responsibility to help guide the club's young players and mould them into future first-teamers. When Atkinson was sacked in 1986, his replacement,
Alex Ferguson, decided to keep Harrison on as youth coach. Dissatisfied with the number of players coming through the United youth system, Ferguson called a meeting with Harrison to discuss potential improvements. Harrison pointed out that he had already made
Norman Whiteside and a couple of others into first team players, but Ferguson argued that this was still not enough. Harrison retorted "Right, we'll do a deal. You get me better-quality players, and I'll get you more youngsters in the first team." Harrison's set-up subsequently produced a crop of first team players that became known as "
Fergie's Fledglings" or "the class of '92". These included
David Beckham,
Ryan Giggs,
Nicky Butt,
Gary Neville and
Robbie Savage. Harrison managed the Manchester United youth team that included many of these players and won the 1992
FA Youth Cup. The group has been described as "one of the best crops of young players in the English game". In 1993, Harrison introduced
Paul Scholes,
Phil Neville and
Keith Gillespie to first team football. In 1995, a Harrison-coached team, captained by Phil Neville, won the FA Youth Cup again. Other players brought through the Manchester United youth team by Harrison include
Mark Hughes,
Norman Whiteside,
Clayton Blackmore and
Graeme Hogg. until he left Manchester United around 2008. From 2000 to 2004, Harrison was assistant manager of the
Wales national football team under Mark Hughes. ==Later life==