Harrison began his football career as a player with his local club, Halifax Town, and made 199 league appearances between 1957 and 1964. After seven years with Halifax, he joined Hartlepools United, where he played for two years before joining Barrow in 1966. At Barrow, he was noted as a strong midfield player who played a key role in securing the club's promotion to the Third Division in 1967. He was at Southport from 1969 to 1971 before returning to Barrow for the 1971–72 season. In all, he made 162 league appearances for Barrow and a further 25 in other competitions, scoring three goals. He left Barrow for Scarborough in 1972. After retiring from playing Harrison entered coaching.
Manchester United
Hired from Everton in June 1981 by new Manchester United manager Ron Atkinson, with whom Harrison had played for the Royal Air Forcefootball team, 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." Ferguson agreed and set about increasing the club's scouting network two-or-threefold. 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. Harrison left Manchester United around 2008.
