Hazard believes De Bruyne need to leave Chelsea in order to ensure he is ready for the World Cup in Brazil.
The 22-year-old has started only four matches for Chelsea since returning to the club from a loan spell with Bundesliga giants Werder Bremen last season.
“For sure, playing at a World Cup without having been in action for a year, I think that’s very difficult,” said Hazard.
“I think for him that leaving and playing, that would be good.
“If we want to get the best out of Kevin, I think that it’s best if he leaves.”