He worked his way up through the youth ranks, until he signed his first professional contract, a two-year deal with Ajax on 21 December 2011, binding him to the club until July 2014.
[6] Sven made 15 appearances under manager Fred Grim, and finishing 14th with Almere CIty FC in the Eerste Divisie.
Before returning to Amsterdam, while his younger brother Lars Nieuwpoort signed a two-year contract with Almere City FC.
[9] On 13 July 2013, Nieuwpoort appeared in a friendly match against De Graafschap, when he was brought in for Joël Veltman in the 60th minute in the 0–3 win in Doetinchem.
[12] On 29 May 2014, it was announced that Nieuwpoort had signed a two-year contract with an option for an additional season with Go Ahead Eagles playing in the Eredivisie.