Born in Aberdeen in 1946 the diminutive wing half began his career with local youth side Thistle Lads’ Club before coming to the attention of Old Trafford scouts in 1961.
A broken leg sustained in his final appearance for the Aberdeen side delayed him joining United but he eventually signed apprentice forms with the English club in July 1962, turning professional 14 months later.
Fitzpatrick helped United to FA Youth Cup sucess in 1964 playing alongside the likes of George Best and made his senior debut in February 1965 as an 18-year-old.
He made history in October of that year when he replaced fellow Scot and Aberdonian Denis Law, thus becoming the club’s first ever substitute in a Football League match.
He found gametime limited with Nobby Stiles and Pat Crerand keeping him out of the team but his versatility led to him making more regular appearances from the 1967/68 season in a variety of positions.
Fitzpatrick eventually displaced Shay Brennan at right-back, but injuries had started to disrupt his career. He had already been sidelined for four months with an injury sustained against Tottenham in November 1969 and although he missed just seven matches during the 1970/71 season, he suffered a recurrence of the injury and played just once the following year.
He underwent four operations in a bid to cure the issue and made a comeback at the start of the 1972/73 season but played just six more times for the first team before being advised to hang up his boots at the age of just 2
Fitzpatrick retired having made 147 appearances for United, scoring ten goals, and returned to his hometown where he carved out a career as a wine importer.
A statement from Manchester United read: "Manchester United would like to send condolences to the family and friends of John Fitzpatrick, who has sadly passed away at the age of 74.
"The Scotsman will always be part of the club's history after becoming the first substitute used by the club in a league match, replacing Denis Law during a defeat to Tottenham in October, 1965.”