After having been head coach of NEC for one year and despite the good performance of the club, he unexpectedly resigned from his post and left, due to differences in perspective between him and the board.
[3] In January 2006, it was announced that Lok was appointed new coach of NAC Breda, who had sacked their manager Ton Lokhoff a few days before.
[4] Soon after his arrival, he had a clash with Pierre van Hooijdonk, who left to join Feyenoord in the winter break.
[10] In the summer of 2009, Lok left his position as coach of Jong Twente and succeeded Mohammed Allach as technical manager at the club.
Twente became Eredivisie champions for the first time in club history in 2010, with Lok active as technical manager.
In March 2015, Lok left Twente and started One Goal Sportmanagament with Jan Streuer, former Shakhtar Donetsk chief scout.