Born in Ridgeway, Derbyshire, Pearson joined Manchester United as a trainee in 1955 and signed professional forms two years later. He made his first-team debut as an 18-year-old on 19 February 1958 as part of the makeshift side that beat Sheffield Wednesday in United's first game after the Munich Air Crash. He was involved in two of the three goals, and "The Times"' correspondent was impressed: Pearson, nicknamed "Pancho" due to the Mexican appearance that his sideburns gave him, played for the club until 1963, making 80 appearances and scoring 14 goals, when he was sold to Sheffield Wednesday for a £17,000 fee. He did not make United's side for the 1963 FA Cup Final, where they defeated Leicester City 3-1 to clinch their first major trophy of the post-Munich era.