[3] McManus was born in Falkirk, Scotland but moved to the south-east of England as a child, where he represented Surrey Schools.
[5] In July 1984, he signed a professional contract and was loaned to Newport County in August and September 1985, where he played five matches without scoring.
[2] He made his first-team debut on 11 March 1986 when he replaced Danny Wallace at outside-right for the First Division match against Queens Park Rangers at Loftus Road.
[6] McManus scored in the 23rd minute with a header from a deep cross from David Armstrong as the Saints recorded a 2–0 victory.
[1] He was a member of the Lillestrøm team that reached the final of the Norwegian Football Cup in 1992, where they were beaten 3–2 by Rosenborg.