De Bruyne spent his first 18 months as a Chelsea player on loan, first and Genk and then at Werder Bremen, and has been linked with a return to the Bundesliga after finding opportunities tough to come by at Stamford Bridge under Jose Mourinho.
Hazard thinks De Bruyne should seek first-team football elsewhere, although was not specific over whether his team-mate should seek a permanent switch or another loan move.
"For sure, playing at a World Cup without having been in action for a year, I think that's very difficult," Hazard told Belgian broadcaster VRT. "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."