He returned to Belgium in 2010 by joining Oud-Heverlee Leuven and was part of the team achieving promotion to the Belgian Pro League.
In February 2014, he was relieved of his coaching duties at Dender EH due to bad result, but stayed with the team as player.
On 31 December 2021, Hayen was announced as manager of Cymru Premier club Haverfordwest County on an initial 18-month contract.
[1] This was duly extended for a further 12 months upon confirmation of safety towards the end of the 2021–22 season, after an excellent run of form.
[3][4] On 18 March 2024, he was appointed as caretaker manager of Club Brugge, following the dismissal of Ronny Deila.