Donk impressed in the 2005–06 season at RKC Waalwijk and with an expiring contract, he wanted to make a step up to a higher level.

Donk chose to go to AZ as a replacement for Joris Mathijsen who had been sold to German club Hamburger SV, thinking it to be the best for his development.

Initially, AZ intended to loan Donk to Waalwijk, but he stated his intent to stay at the club in an attempt to push into the first team.

[9] In 2007 Donk was called up by Jong Oranje coach Foppe de Haan to be part of his squad for the 2007 UEFA European Under-21 Football Championship held in the Netherlands.

After the Dutch qualified for the semi-final and Olympics Donk took off his football jersey to reveal another shirt having the text "Dit toernooi is voor jou, ik hou van je."

Born in the Netherlands and of Surinamese descent, Donk was called up for a friendly match with the Suriname national football team in 2014, but was not given permission to join the squad.

He made his debut, as a team captain, on 24 March 2021 in a World Cup qualifier against the Cayman Islands and scored the second goal in a 3–0 victory.