The duo are international team-mates for Belgium and have struck up a close friendship.
Both wingers built up their reputations in the Premier League, although Hazard has certainly progressed further than Januzaj.
Jose Mourinho sent the 22-year-old on a season-long loan to Sunderland where he admits he has endured a difficult campaign.
The Black Cats sit bottom of the table, and while Januzaj has made 19 top-flight appearances, the attacker has failed to score and has just three assists.
Premier League duo Eden Hazard and Adnan Januzaj have spent time together playing for Belgium
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He is a good friend to me. He is a top player
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Despite his problems, the United man believes he can take plenty from Hazard’s game at Chelsea, as he watched plenty of the former Lille man in his spare time.
“I can learn from him,” Januzaj told the Sunderland Echo. “He has more experience than me.
“When you are playing against Chelsea there are more players who can make a difference so it’s harder to track all of them.
“I watch a lot of games in the PL when I have free time and that’s where I learn.
“He is a good friend to me. He is a top player. Whenever he has the ball he is dangerous.
“He is one of the best players in the Premier League, if not the best, he has so much talent now and I know him well.”
Eden Hazard has attracted interest from Zinedine Zidane at Real Madrid for his sublime form at Stamford Bridge.
But Antonio Conte won’t want to lose the Chelsea star, who has been instrumental in the Blues’ push for the title.
Meanwhile, Januzaj could struggle to earn a future back at Old Trafford, with a permanent summer exit possible.