The son of ex-Arsenal professional Tony Winston, Sam is a midfielder who began his career as a trainee with Tottenham Hotspur. Whilst as a 15 year old Associate Schoolboy, he was part of the Spurs squad that reached the final of the Southern Junior Floodlit Cup. He transferred his traineeship to Carrow Road in the summer of 1995 as he felt he had a better chance with a smaller club.

Alas this was not to be and Sam returned to London with Leyton Orient. He did however make 36 appearances for the youth team in the 1995/96 season scoring 9 goals. Three appearances, all as substitute, were made for the Reserves. Sam made 11 league appearances for Orient by the end of the 1996/97 season but joined Conference side Yeovil. Despite a successful goals per game ratio for Yeovil, Sam was allowed to return to North London and join Chesham United.

The June 1999 edition of Team Talk magazine revealed that Sam had joined Sutton United on loan and this later became permanent. Despite regularly scoring throughout 1999/2000, Sammy's goals could not prevent Sutton being relegated from the Conference. However Sammy returned to the Conference in July 2000 when he signed for Kingstonian. He showed his potential by netting Kingstonian's only goal in a 3-1 defeat against Chelsea on 22nd July 2000 with the Blues fielding £15million Jimmy Floyd Hasselbaink, £4million Einur Gudjohnsen, £5million Mario Stanic, Roberto Di Matteo etc.

Sammy suffered another relegation in April 2001 when Kingstonian followed Sutton out of the Conference and into the Rymans League. The resulting financial chaos that Kingstonian suffered saw them release their highest earners, including Sammy, in October 2001. Sammy quickly found a new club signing for Slough Town on the 9th November 2001. His stay at Slough lasted approximately 18months as he switched to Boreham Wood at the end of June 2003.

Sammy scored 58 goals in a staggering 94 starts for the club between June 2003 and February 2005. In 2003/4 Winston bagged 41 goals just four short of Shaun Marshall's club record haul in the 1997/98 season. Following the departure of former manager Steve Browne, Winston stayed loyal to the club, choosing not to join the exodus of players that Browne commanded. Winston started the 2004/5 season in a similar vein, hitting 13 goals in as many starts, with hopes high for another scintillating season, after forging a fine partnership with Robbie Reinelt. However the club's decision to release Reinelt and two short-lived partnerships with Wayne Cort and Miguel De Souza unsettled the striker. Ian Cooper's arrival sparked a resurrection in Winston's goalscoring appetite, netting five times in six games. But when Cooper joined Waltham Forest, Winston was left in a lone striker role, and his lack of support had an adverse effect on the man who scooped both the Supporters' and Chairman's Player of the Year Awards last season.

Following a three-match ban he received for a rather harsh sending-off against Fisher Athletic back in December and a poor run of form, Sammy was transfer-listed by chairman Danny Hunter in January 2005 , 'to get a reaction'. The striker was the subject of huge interest from a number of clubs. Sammy opted to join East Thurrock United towards the end of February 2005. United manager Lee Patterson works with Sammy on the London Fire Brigade.

The following August saw Sammy playing for Harlow Town. In March 2006, Sammy joined Uxbridge on loan. Although Sammy was Harlow's leading goalscorer in the 2006/7 season, he was allowed to join Ryman League side Leyton in the summer of 2007.

After playing for Potters Bar Town during the beginning part of the 2008/9 season, Sammy joined Enfield Town in early February 2009 whom have the aforementiond Steve Browne as Assistant Manager.