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 that 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 needs not be afraid of anyone when it features 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. The people might expect too much from Belgium."