Slory became the club's top scorer with 12 goals, made his debut in the Netherlands national football team and earned a transfer to Feyenoord.

The Dutch Eerste Divisie clubs AZ and Telstar, both based in North Holland, were interested in the youngster.

[3] On 4 November 2001, Slory was named in the starting line-up of the home match against HFC Haarlem (0–1) for the first and only time of the season.

On 31 March 2006, Excelsior won the home match against championship favorite VVV-Venlo (3–1), securing the Eerste Divisie 2005–06 title.

However, Slory impressed in the early weeks of the season, scoring five goals in the first ten matches and also had four assists to his name.

[14] Due to Slory's impressive start of the season, the winger was watched by scouts from various domestic and foreign clubs.

[17] The winger also scored in the home trashing against Heracles Almelo (6–1)[18] and twice in the away match against ADO Den Haag (2–2),[19] both clubs also fighting against relegation.

Slory's excellent dribble in the 20th minute caused AZ goalkeeper Boy Waterman to make a foul.

Slory was part of Feyenoord's starting line-up in the away match against FC Utrecht (0–3), but collided with opposing goalkeeper Franck Grandel after 17 minutes.

[25] As a result of the heavy rivalry between the two sides, a threatening note was delivered at Slory's home address after the match: "You better score the third opportunity, otherwise you must move!".

On 17 July 2009, Slory was involved in a fight with teammate Karim El Ahmadi on a pre-season training in Óbidos, Portugal.

Despite the good start of the season, minor incidents continued to occur and Slory slowly lost his place within the first eleven.

[33] On 22 November 2009, Slory was fined for signing autographs at a school in Barendrecht, while he was reportedly ill and unable to attend the club's training session.

[34] Combined with Slory's expiring contract, the player was free to join a new club during the winter transfer period.

Slory made 6 league appearances for West Bromwich Albion during the 2009/10 season with only one start and the rest coming off the bench.

Slory did not succeed in establishing himself as first choice in the Sofia team's line-up and eventually cancelled his contract with the Bulgarian side.

On 20 December 2010, it was announced that Slory had signed as a guest player for A-league side Adelaide United, a contract which allows him to make a maximum of 10 appearances for the club.

Adelaide United has also left the door open for the possibility of Slory staying on beyond the end of the 2010/11 A-League season.

[38] Slory claims he has lost the passion and commitment to football, and hopes to return to the Netherlands and start up a business.

[38] Slory returned to Netherlands and played with amateur clubs BVV Barendrecht and VDL Maassluis, while completing his coaching course.

[39] On 10 April, Slory was demoted to the reserves alongside Mart Lieder and Jordy van Deelen by head coach Jan Everse.

[40] Slory was born in Suriname, a former Dutch territory, and was eligible to represent either the Surinam national team or the Netherlands national team, he chose to represent the Netherlands like many other Surinamese born footballers such as Edgar Davids, Clarence Seedorf and Jimmy Hasselbaink.

As a result of his excellent performance at Excelsior in the Eredivisie season 2006–07, Slory received an invitation by the Netherlands coach Marco van Basten.

After a foul on Slory, the Netherlands received a penalty kick in the 32nd minute of game, which was scored by Rafael van der Vaart.