On 3 July 2013, Castelen returned to his homeland and its top division, joining RKC. Roughly one year later, he signed a two-year contract with A-League club Western Sydney Wanderers FC. He participated with his new team at the 2014 FIFA Club World Cup, scoring the opener against ES Sétif in the fifth-place match, which ended in a penalty shootout loss after a 2–2 draw.