Eden Hazard wants Kevin de Bruyne to get out of Stamford Bridge so he can be at his best for Belgium at next summer's World Cup.
De Bruyne was tipped to star for Chelsea this season after experiencing a successful loan spell at Werder Bremen last term.
However, the Belgian has fallen out of favour under Jose Mourinho and has so far started just two Premier League matches for the Blues.
The 22-year-old has subsequently been linked with a January move away from Chelsea, with Bundesliga outfit Schalke 04 reported to be interested.
And Hazard has backed a potential move for his compatriot, saying that if his situation continues at Stamford Bridge, he won't be able to bring his best form to Brazil.
"If he does not play, it is better for him to leave," Hazard is quoted as saying in Belgian newspaper 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."
The quotes from the Chelsea and Belgium winger reiterate the thoughts of national coach Marc Wilmots, who has also told De Bruyne to leave Chelsea as soon as possible in order to ensure his place in Belgium's World Cup place.