Koenders then joined to RKC Waalwijk and made his debut in the professional football in the 2006–07 season, playing 30 matches.
There, he would make his European debut as a starter in a 1–1 away draw in the group stage of the UEFA Cup against Zenit Saint Petersburg.
[4] In summer 2016, Koenders joined Romanian club Concordia Chiajna for the 2016–17 season.
One month later, in June, DWS announced that Koenders also would be playing for the club.
This biographical article related to association football in the Netherlands, about a defender, is a stub.