Collin believes the midfielder needs to make improvements to his all-round game - for both club and country.
He told Nieuwsblad: "He has technique, explosiveness and positioning. At some point he will have to work on defending, and he has no choice with that.
"But I have confidence that [Belgium manager] Marc Wilmots will occasionally give him a kick up his a**.
"The learning process is slow but good. If (Lionel) Messi should work for the team and defend, then I see no reason why Hazard should not do likewise."