Both players featured in Belgium's 2-0 defeat against Colombia on Thursday, but De Bruyne has found first-team appearances at Chelsea hard to come by.
Belgium coach Mark Wilmots recently suggested a move away from Stamford Bridge could prove beneficial, and Hazard has echoed those sentiments.
"If he does not play, it is better for him to leave," Hazard told Het Nieuwsblad.
"Playing a World Cup after having not played for a year... is very difficult.
"If we want to get the best from Kevin in the future it is better that he leaves. But he's a big boy. He must make his own choices."
As for Belgium's World Cup hopes, Hazard is eager for his team to take things one step at a time in Brazil.
However, he also feels Belgium need not be afraid of anyone when they feature in the premier international tournament for the first time since 2002.
"The first aim must be to survive the first round because we still do not know the draw but we should not be afraid of anyone because we have a very good team," he continued.
"We have no one who has already played in a tournament (such as this). The people might expect too much from Belgium."
‘I don’t think Liverpool would look at Ollie Watkins, a striker isn’t a pressing issue for them – it’s Arsenal who need one’ Former Reds star explains why his old club don’t need an out-and-out forward this summer
‘He’ll still be playing at 40 at a good level because he’s in such good shape and looks after himself so well. He does everything to be a top professional’: Ex-Liverpool coach insists Mohamed Salah has plenty more miles in the tank
