[2][3] He made his debut at Millwall, having been associated with the club since the age of 13, and also represented Tottenham Hotspur, Southampton, Liverpool, West Ham United, Crystal Palace, Queens Park Rangers and Swindon Town during a professional career spanning 17 years.
He broke his leg on his Tottenham debut against Liverpool and made only 11 appearances for Spurs, his only goal coming in a 2–1 defeat to third tier Port Vale in the 1987–88 FA Cup.
[6] In the 1991–92 season, Ruddock was a member of the Southampton side that reached the final of the Zenith Data Systems Cup, where they were beaten in extra time 3–2 by Nottingham Forest.
[8] After three years on the south coast, he was enticed back to Tottenham by Terry Venables in May 1992, with the tribunal setting the transfer fee at a "ridiculous" £750,000.
[13] At Liverpool, Ruddock was part of the squad of the 1990s under Roy Evans, known as the "Spice Boys", that included David James, Robbie Fowler, Jamie Redknapp, Jason McAteer, Steve McManaman and Stan Collymore, but left in 1998 when new coach Gérard Houllier joined.
[14] In July 1998, Ruddock moved to West Ham United for a fee of £300,000 making his debut on 15 August 1998 in a 1–0 away win against Sheffield Wednesday.
[16] In 56 games for West Ham, he scored three goals, was booked 14 times and sent-off once, in December 1998, in a 4–0 away defeat to Leeds United, for a dangerous tackle on Harry Kewell.
[17] In 2000, Ruddock moved to Crystal Palace on a free transfer, spending one season there before signing for Division Two side Swindon Town.
[20] Relations turned sour when Ruddock refused to quit after being advised to do so by a specialist; during a period of time where the club was in serious financial difficulties.
He took the club to an employment tribunal and in December 2002, received £57,000, representing money lost in wages and loyalty payments, with an agreement to terminate his contract as player/coach.
On 16 November 1994, he won his only senior cap for England, playing in a friendly against Nigeria when Terry Venables was the national team's coach.
[30] He appeared again in April 2013 as a member of the Manlab team representing China at the Rock, Paper, Scissors world championships.